Diffraction

27 Jun 2013

Solid state, Semiconductors, Electrochemistry, and Nanowires for Solar Cells

Submitted by Jeremiah Duncan, Plymouth State University
Evaluation Methods: 

This learning object has not yet been tested.

Evaluation Results: 

This learning object has not yet been tested.

Description: 

This Literature Discussion learning object (LO) is based on the paper “Template Electrodeposition of Single-Phase p- and n-Type Copper Indium Diselenide (CuInSe2) Nanowire Arrays,” Emil A. Hernández-Pagán, Wei Wang, and Thomas E. Mallouk, ACS Nano, 2011, 5 (4), pp 3237–3241. DOI: 10.1021/nn200373k

This paper is about the synthesis and characterization of CuInSe2 nanowires using templates and electrodeposition. It is found that varying the potential of the electrodeposition influences the relative stoichiometry of the Cu and In atoms. Lower (more negative) potentials result in In-rich, n-type nanowires and higher potentials result in Cu-rich, p-type nanowires. These materials may find utility in solar cells, and nanowire geometry is predicted to result in more efficient solar-to-electrical conversion.

This paper covers topics in the following four categories: 1) electrochemistry, 2) nanomaterials, 3) semiconductors, and 4) solid state structures (including diffraction). Because these topics may be covered in different orders by different instructors, this LO has been designed to be modular to allow this Literature Discussion to occur at various points in the curriculum. Learning goals and relevant guiding questions have thus been grouped under each of these categories to help focus discussions. This LO may serve as a good review at the end of a course that covers all of these categories, though there is more here than can likely be covered in a single class. Therefore, it is assumed that, when implemented, instructors will choose to use individual learning goals/guiding questions or entire categories. Please implement and post any handouts or modifications that you create!

The creators of this learning object gratefully acknowlege Tom Mallouk (The Pennsylvania State University) for his contributions and insights to our group's discussions.

Prerequisites: 
Corequisites: 
Learning Goals: 

In reading this paper and participating in the literature discussion, students will:

Electrochemistry

  1. Calculate concentrations of electrolyte components based on stoichiometry.
  2. Rank elements in order of ease of reduction.
  3. Apply knowledge from the electrochemical series to understanding the synthesis of CuInSe2.
  4. Relate understanding of standard reduction potentials to topics in the current literature.

Nanomaterials

  1. Use TEM images to describe the dimensions of the synthesized nanowires.
  2. Describe a unique property of nanowires relative to the bulk material that may improve their utility in solar cells.
  3. Apply the relationship between grain size and peak broadening in XRD patterns using the Scherrer equation.

Semiconductors

  1. Define p-type and n-type semiconductors.
  2. Understand band diagrams for p-type and n-type semiconductors and for p-n junctions and use these to explain the unique properties of a p-n junction.
  3. Apply basic electron count process to predict doping type in extrinsic semiconductors.
  4. Distinguish the properties of direct and indirect band gap semiconductors.
  5. Describe quantitatively and qualitatively the relationships between semiconductor band gap energy and the absorption and reflection of visible light.
  6. Describe the four-probe method and distinguish between resistance and resistivity.

Solid state

  1. Understand ionic solid unit cells and how similar unit cells relate to each other:
    1. describe the zinc blende structure.
    2. describe the relationship of the zinc blende structure to the chalcopyrite structure.
    3. determine the coordination environments of atoms in the unit cell of chalcopyrite, specifically CuInSe2.
    4. understand the concept of solid solutions and how different ions can occupy the same lattice sites in an extended ionic solid.
  2. Define the nomenclature of Miller indices for lattice planes. Relate a particular set of Miller planes for a material to the unit cell and observed peaks in X-ray powder diffraction patterns.
  3. Calculate and interpret mole ratios from elemental analysis data.
27 Jun 2013

Tuning the band gap of CZT(S,Se) nanocrystals by anion substitution

Submitted by Benny Chan, The College of New Jersey
Evaluation Methods: 

We have not attempted to evaluate this LO.  As we use the LO, we will post the assessment data.

The writers of this LO also wanted to assess the effectiveness of the Concept Map LO of this article (Linked on website) when answering the same set of questions.  We want to assess whether concept mapping of the article would aid in the comprehension of a literature article.  If the students have a measureable increase in understanding, we believe concept mapping an article would be a good, transferable strategy for students to dissect and to understand an article.  

 

Description: 

The paper from the Prieto group, Riha, S. C.; Parkinson, B. A.; Prieto, A. L. J. Am. Chem. Soc. 2011, 133, 15272-15275, is proposed to be an excellent literature article for achieving several learning goals in the understanding of fundamental solid state and materials chemistry. The learning object was developed as a part of the 2013 VIPEr workshop and has not been tested in the classroom. We have developed a set of discussion questions that can be used as a guide for the students. We have also developed a complementary LO, that uses a concept map to help understand the article. We provide additional questions for assessing the concept map. We would appreciate help in testing the effectiveness of the discussion questions with and without the concept map.

The paper in discussion describes the synthesis of CZT(S, Se) nanoparticles that have potential application in the manufacturing of low-cost and environmentally responsible thin-film solar cells. The article reviews the previous literature and explicitly develops testable hypotheses. The as-synthesized nanoparticles are carefully studied by a suite of instrumental techniques including X-ray diffraction, high resolution transmission electron microscopy, and UV-vis spectroscopy. The data from the paper can be used to help students understand the synthesis, characterization, and properties of semiconducting nanomaterials. Furthermore, the paper explains the implications of their finding to further the scientific study of multicomponent chalcogenide nanocrystals.

Prerequisites: 
Corequisites: 
Learning Goals: 

LG1: Find a specific scholarly article and its supporting information from a library resource.

LG2: Explain the effects of solid solution formation on material properties including changes in the empirical formula, unit cell, lattice parameters, and energy band gap.

LG3: Compare multiple analytical techniques that are needed to complete a scientific study.

LG4: Use data to justify the goals of the article.

LG5: List the advantages and disadvantages of CZT(S,Se) nanoparticles as components in next generation photovoltaic devices.

LG6: Evaluate the usefulness of a concept map to connect multiple ideas in this primary literature article.

Implementation Notes: 

We have not attempted to implement this LO.  We imagine that this LO could be used in conjunction with the concept map LO.  We would assume that students could work in small groups to discuss the literature.

 

27 Jun 2013
Evaluation Methods: 

We have currently not evaluated this method.  We believe that this method could be generalized to examine any literature article.  As we test this LO, we will post our assessment data.

The related LO, Tuning the band gap of CZT(S,Se) nanocrystals by anion substitution, contains discussion questions on the article that can be used for additional evaluation.  We have also developed questions that we believe would use this concept map specifically.  We would enjoy comments on how these two related LOs are being used and assessing whether concept mapping helps students understand literature articles.

Description: 

Concept maps are a visual way to organize and represent information. In this literature discussion, we introduce a novel technique for teaching literature analysis to students where concept maps are used for establishing relationships between the key ideas, theories, procedures, and methods of a proposed literature article. Using the article “Compositionally Tunable Cu2ZnSn(S1-xSex)4 Nanocrystals: Probing the Effect of Se-Inclusion in Mixed Chalcogenide Thin Films” (Riha, S.C.; Parkinson, B.A.; Prieto, A.L. J. Am. Chem. Soc., 2011, 133, 15272-15275.) as a case study, students are asked to identify the key terminology related to the synthesis, properties, analysis, and application of semiconductor nanoparticles and are tasked to develop a concept map interrelating important conceptual ideas and results.

 

Learning Goals: 

LG1:  Identify key words that describe aspects synthesis, applications, properties, and analysis

LG2:  Create a concept map by identifying how the key words are related

Corequisites: 
Prerequisites: 
Implementation Notes: 

Supplies Needed:

- packs of sticky notes

- 3’x5’ poster paper or large sticky note pads

- markers

 

Before class

Students will be asked to read the paper before class and write down some key words and terms. There is an attached student handout to facilitate this process; this document briefly describes concept maps to students and gives three larger categories for students to begin grouping their key terms.

(The in-class activity may be implemented in a variety of ways to meet your classroom needs. Here we suggest a model conducive for small group work.)

In class

Begin with a class discussion about the terms or ideas that were found while reading the paper. As a group you might want to place these ideas into one of the three categories: synthesis, analysis, or properties. (Perhaps come up with several more at this point.) Students may then break into smaller groups and focus on one category (if you have a large class, you may choose to have multiple groups for each category). Provide each group with sticky notes and instruct them to write one term on each sticky note (a dry-erase board or large poster paper can also be used in place of sticky notes). They should begin constructing a concept map for this category. Ask students to consider the relationship between any concepts that are connected by lines and perhaps to write a short phrase that describes this relationship.

When these groups have developed the section of the concept map in some detail, bring the class back together to construct the larger concept map integrating the individual maps prepared by each group. Begin to think about the inter-connection of concepts within different categories.

There is a related learning object with discussion questions related to this paper, which may be used as a problem set for homework, guidance for discussion, or a wrap-up activity.

**NOTE** The goal of this learning object is to create a concept map for this article. One example of a concept map for this article has been provided in the instructors information. However, it must be noted that the map generated by your class will not necessarily be identical to the one that has been provided. It is expected that there will be variations between the different concept maps generated.

25 Jun 2013

The Synthesis and Characterization of Cobalt Spinels

Submitted by Rebecca Ricciardo, The Ohio State University
Evaluation Methods: 

Students complete pre- and post-lab questions; these are within the document. Upon completion of the lab, the student is to write a lab report. A lab report is written in a format similar to that of a paper submitted for publication. Sections include the title & authors, abstract, introduction, experimental, results, discussion, conclusion and references.

Evaluation Results: 

The average score for the prelab assignements was 65% with a high of 100% and a low of 35%. The average score for lab reports was 92% with a high of 100% and a low of 71%. 

Students were able to index the patterns using the supplement (attached) as a guide. 

Description: 

In this lab, students will use solid-state methods to synthesize cobalt and chromium spinels, ZnCr2O4, ZnCo2O4, CoAl2O4, and CoCr2O4. They will (1) characterize their structure with X-ray powder diffraction (XRD) and (2) characterize the color using UV-Vis diffuse reflectance spectroscopy.

Corequisites: 
Prerequisites: 
Learning Goals: 

Upon completing this lab, students will:

  • Know how to synthesize polycrystalline materials using solid state synthesis techniques.
  • Gain experience preparing solid samples for diffraction analysis and collecting XRD data.
  • Be able to index XRD patterns from cubic materials to determine unit cell parameters.
  • Relate reflectance spectra to the visible colors of materials.

 

Equipment needs: 

Analytical balances

Mortars and pestles (agate or porcelain)

Crucibles (alumina or porcelain)

High temperature furnace (1000˚C)

Powder X-ray diffractometer

UV-Vis spectrometer equipped to do diffuse reflectance

Implementation Notes: 

This lab is the first lab in an upper level inorganic laboratory course. It is completed first, because the students must weigh out reagents and grind them in a mortar and pestle and then heat them for 8 hours at 1000˚C. The synthesis does not take a full lab period, which allows time for the first-day housekeeping items to be distributed and discussed. During the second lab period, student samples are returned and the students collect their XRD data and UV-Vis data. There is enough time for students to begin working through the analysis in class.

Note: This lab lends itself to many adaptations.

  • If there is no XRD access readily available for students, patterns may be provided so that students can index these, even if they have not collected the data.
  • The electronic transitions of these compounds may be analyzed with more detail (ie. assigning transitions).
  • Magnetic measurements may be made and the number of unpaired electrons deduced (this is Exp 3 that is referred to in the attached lab document).

 

Time Required: 
Sample must be heated for 8-10 hours, so the synthesis and characterization must be completed at two separate times: (1) 1-hour period for synthesis of compounds and (2) a 3-hour lab period for analysis.
31 May 2013

Lithium Diazenide Surprise!

Submitted by Maggie Geselbracht, Reed College
Evaluation Methods: 

During conference, I gave students direct feedback on the MO diagrams and cartoons of MO surfaces their groups had drawn on the board.  As this conference was scheduled the day before a problem set was due, this feedback was helpful to students in gaining confidence drawing MO diagrams of diatomics. 

I collected the discussion questions and graded these on a 10 point scale, 1.5 points for question 1, 0.5 point for question 3, 3 points for question 7, 1 point for questions 2, 4, 5, and 6, and 1 point for effort.

Evaluation Results: 

Out of the 15 students that turned in written answers, 6 (40%) earned 9-10 points, 5 students (33%) earned 6.5-7 points, another 2 students (13%) earned 5-5.5 points, and 2 students (13%) earned < 5 points.  On the MO diagrams, I told them I did not care if they invoked sp­-mixing or not in their diagrams, but that they needed to be consistent with their choice.  In other words, if the 3 sg energy level was shown above the 1 πu energy levels in their diagram, then I expected to see evidence of sp­-mixing in their molecular orbital surface cartoons.  About half of the students chose to use sp­-mixing in their diagrams, but most of them did not show evidence of sp­-mixing in the molecular orbital surfaces.  Others that chose to invoke sp­-mixing did not shift the MO energy levels correctly; the common mistake was elevating the 2 su* energy level above the 1 πu energy levels rather than the 3 sg energy level.  Nearly all students that have read this paper find it approachable and understand the major conclusions and how these were reached after the discussion.

 

Description: 

Students in a sophomore-level inorganic chemistry course were asked to read the paper “High-Pressure Synthesis and Characterization of the Alkali Diazenide Li2N2” (Angew. Chem. Int. Ed. 2012, 51, 1873-1875. DOI: 10.1002/anie.201108252) in preparation for a class discussion.  For many students, this was a first exposure to reading the primary literature. 

In this paper, the authors describe the surprising stability of lithium diazenide, Li2N2.  In contrast with the increasing stability of peroxides and superoxides with the heavier alkali metals, the first alkali metal diazenide that was isolated was not the rubidium or cesium salt but rather the lithium salt (hence the surprise)!  The black, metallic-looking Li2N2 was synthesized at high pressure and high temperature by the decomposition of lithium azide, LiN3.  The crystal structure of Li2N2 was determined by Rietveld refinement of powder X-ray diffraction data and relevant bond distances were compared to diazene, H2N2, and the alkaline earth diazenides, CaN2, SrN2, and BaN2.  The authors also report evidence from infrared spectroscopy of nitrogen-nitrogen bonds in Li2N2.   Electronic band structure calculations suggest metallic behavior for Li2N2 and antibonding characteristics for the conduction electrons consistent with the molecular orbital description of the isolated diazenide ion.

Course Level: 
Prerequisites: 
Corequisites: 
Learning Goals: 

After reading and discussing this paper, a student will be able to:

  • Articulate the underlying problem and motivations driving the research presented in the paper.
  • Explain the collection of experimental data that lead to figures and tables presented in the paper.
  • Describe the important conclusions of the paper and the evidence presented by the authors to support these conclusions.
  • Gain confidence reading a paper from the primary literature in inorganic chemistry.
  • Describe periodic trends in the descriptive chemistry observed for the alkali metals with oxygen and for the alkali metals with nitrogen.
  • Interpret images of a unit cell to deduce stoichiometry and notable coordination features of an extended structure.
  • Draw the molecular orbital diagram of a homonuclear diatomic species and use the MO diagram to predict the bond order and magnetic properties of the diazenide ion.
Implementation Notes: 

Students in a sophomore-level inorganic chemistry course read the paper "High-Pressure Synthesis and Characterization of the Alkali Diazenide Li2N2" prior to a class discussion, held during a conference session.  A link to the pdf file was posted to the course Moodle, and students were asked to complete the short list of discussion questions (attached below as a Word document) prior to coming to conference.  I also used the Jmol resource embedded in a course Moodle page to display the unit cell of the Li2N2 structure (the pdb file that I used as the input for Jmol is attached below.) On the Moodle page with the Jmol structure, I told students, “Sorry, I don't know how to make Jmol draw the boundaries of the unit cell!  To guide your eye, there are lithium atoms (in lavendar) at all 8 corners of the unit cell.”  This Jmol model was intended to help students answer questions 4 and 5 in the attached list of questions in addition to Figure 2 from the paper.

I used this learning object during the past two years at different times during my course.  In Spring 2012, the paper was assigned in week 4 of the semester, after covering periodic trends in atomic properties, ionic structures, unit cells, stoichiometries of extended structures, basic X-ray powder diffraction, and Lewis structures.  In Spring 2013, the paper was assigned in week 9 of the semester, after MO theory of diatomics was also covered in addition to the previous topics.  The attached discussion questions were from the Spring 2013 version.

During conference, we used the discussion questions as a guide to walk through the paper.  I explained to students how to access the Supporting Information for a paper and the varying utility of this information, depending on the article.  In this case, the Supporting Information is quite helpful, and we talked through key figures and tables in both the paper and in the Supporting Information.  We also discussed the synthesis, and I answered some questions on the characterization methods, explaining briefly what Rietveld refinement is and how the results in Table 1 and Figure 1 are correlated.  For more information on the Rietveld refinement method, see the Web Resource on Powder Diffraction Crystallography Instructional Materials.  Finally, we took the last 10 minutes of conference, and I made all the students get up and in small groups, draw the MO diagram and molecular orbital surfaces for (N2)2– on the white boards around the room.  I circulated and made comments and corrections to each group on their MO diagrams.  

I also used this paper for one student as part of our Junior Qualifying Exam in Inorganic Chemistry.  In this format, the student has 3 days to read the paper and learn about it before taking a 30 minute oral exam, which takes the form of a question-and-answer based discussion of the paper.  For the Junior Qual, we spent most of the time discussing the diffraction analysis of the material, molecular orbital theory of the diazenide ion, and a brief discussion of the properties of lithium diazenide.

Finally, although I have not done so yet, I intend to use this paper in my Advanced Inorganic Chemistry course where we cover the electronic band structure of extended solids in more detail. Our discussions in Advanced I-chem are based on Roald Hoffmann’s book, Solids and Surfaces: A Chemist’s View of Bonding in Extended Structures.  The details of the Li2N2 electronic band structure calculations provided in the Supporting Information for this paper are an excellent illustration of many of the key concepts presented in Hoffmann’s book.

Time Required: 
50 minutes
1 Apr 2013

Online Courses Directory

Submitted by Adam R. Johnson, Harvey Mudd College
Description: 

This website is a free and comprehensive resource that is a collection of open college courses that spans videos, audio lectures, and notes given by professors at a variety of universities. The website is designed to be friendly and designed to be easily accessed on any mobile device.

Course Level: 
Prerequisites: 
Corequisites: 
25 Jan 2013

University of Cambridge Teaching and Learning Packages

Submitted by Barbara Reisner, James Madison University
Description: 

These are a group of outstanding resources for materials science and solid state chemistry. They are all tutorials with Flash animation. I find these to be an excellent review for myself and an excellent primer for my students. Because there are so many useful tutorials on the site, I've highlighted the ones that I think are most appropriate for use in an undergraduate curriculum. These range from introductory to advanced material.

Crystallography & Diffraction

Analytical Techniques

 

Materials Properties

Solid State Meets Physical Chemistry

The individual resources are referenced that I think are useful are referenced above. There is a reference to the TLP (Teaching and Learning Program) website below. I've also included the link to teaching in Materials Science & Metallurgy at Cambridge. If you dig down to some of the web resources below, you can access some of their teaching resources.

The cc license was chosen in accord with what is on the Cambridge website. 

Prerequisites: 
Course Level: 
Corequisites: 
Implementation Notes: 

At the moment, I mostly use these as a review for myself and my research students. I could see using these as supplementary materials in class in an effort to flip the classroom on some of these topics.

 

19 Jul 2012
Description: 

This is a great web resource for all types of nano materials.  There are lesson plans, demos, activites, labs and lots of background information.  It is very easy to navigate and there are videos of the labs so you can see each step - very useful when doing a type of synthesis or technique new to you.

Prerequisites: 
Corequisites: 
Implementation Notes: 

Students and instructors are able to watch videos and view safety info on a large number of nanomaterials labs and activities.  Truly a variety of skill and equipment levels but very well explained so you know what to expect.

I have used the ferrofluid synthesis proceedure and added some questions and information from the J. Chem. Ed. article listed on the site.  It works very well but pay attention to the notes they include - the iron II chloride needs to be fresh so buy small bottles.

Time Required: 
5 minutes if you know what you want, hours to read it all.
17 Jul 2012

Colored Note Cards as a Quick and Cheap Substitute for Clickers

Submitted by Chris Bradley, Mount St. Mary's University
Evaluation Methods: 

Use of the cards gives a rough "eyeball" evaluation of student learning throughout a lecture. Using the cards, for me at least, also provides a gauge of attendance as well and also if it waxes or wanes during the class period.

Description: 

For many years I have resisted using clickers, mainly because at our university there is no standard universal clicker. I wanted to keep student costs as low as possible but also desired the type of live feedback during a lecture that clicker questions can provide. In both my general chem. (200-300 students) and upper division courses (50-75 students), I now pass out 4 or 5 colored notecards on the first day of class and make sure everyone has one of each color. I then do clicker style questions and color code the different answer choices in powerpoint and ask them to hold up their choice after 15-60 seconds depending on the question. This has worked well to provide me instant feedback on difficult topics and doesn't end up singling out any particular student, which most students detest in larger lecture courses.   

 

Learning Goals: 

Students are able to provide feedback to the instructor on questions quickly and "anonymously" and allow one to adjust the direction of a lecture on the fly.   

Prerequisites: 
Corequisites: 
Equipment needs: 

NA

Implementation Notes: 

I typically use between 4-6 clicker questions during a 50 minute lecture. I'm sure someone could use more/less based on an individual's needs. I think the key is to use clicker style questions from the beginning of the class on a daily basis to remind students to bring the note cards in a book/binder/bag. This is really the only problem I have encountered- students often forget their cards. It is probably a wash though, as I'm sure students can also forget clickers.  

Time Required: 
1-5 minutes (depending on the problem)
26 Jun 2011
Evaluation Methods: 

I was most interested in assessing if this was an accessible paper for students at this level (2nd year inorganic, post general chemistry).  I collected their annotated copies of the paper and gave them a “participation” score for reading the paper.  I looked through the annotated copies, comparing what terms different students highlighted as being unfamiliar and collecting them in the attached document.

Ultimately, students were responsible for the larger “take-home” content message as there was a question on the final exam relating directly to this paper discussion.  This assessment question is also posted on VIPEr (see related activities link above).

 

Evaluation Results: 

Several students mentioned anecdotally that this paper was very understandable.  Furthermore, by highlighting what they did not know, they realized that they actually understood quite a bit! A Word file is attached that lists the terms that one or more students marked as “unfamiliar” on their annotated copy of the pdf file for this article.

While I did not collect or evaluate written responses to the discussion questions, students were better prepared to answer some questions more than others.  In particular, they were all stumped (long silence!) when I asked question 5.

Description: 

This paper from Chemistry: A European Journal by Manolis Manos and Mercouri Kanatzidis (link provided below in Web Resources) describes the ion-exchange chemistry of a layered sulfide (KMS-1) that exhibits an enhanced preference for soft metal cations (Cd2+, Pb2+, and Hg2+) replacing K+ in between the metal sulfide layers of KMS-1.  Not only does this paper provide a practical application of hard-soft acid-base theory (HSAB), but it provides an accessible introduction to the technical literature for undergraduates, particularly at the first or second-year level.  This learning object was used to illustrate hard-soft acid-base theory, the structures of extended solids, solid solution formation, ion-exchange chemistry, and the analysis of structural changes by X-ray powder diffraction.

Students in a second-year inorganic chemistry course were asked to read this paper in preparation for a class discussion (see further details in implementation notes).  For many students, this was a first or second exposure to reading the primary literature.

 

Corequisites: 
Prerequisites: 
Course Level: 
Learning Goals: 

After reading and discussing this paper, a student will be able to:

• Articulate the underlying problem and motivations driving the research presented in the paper
• Explain the collection of experimental data that lead to figures and tables presented in the paper and describe the interpretation of these results by the authors
• Discuss the relative importance of various thermodynamic factors predicting the favorability of ion-exchange reactions
• Gain confidence reading a paper from the primary literature in inorganic chemistry

 

Implementation Notes: 

Students in a second-year inorganic chemistry course read the paper "Sequestration of Heavy Metals from Water with Layered Metal Sulfides" prior to a class discussion.  The pdf file was posted to the course Moodle, and students were asked to “Annotate” their copy (either in printed or electronic form) to highlight terms or sections of text that they did not understand.  At the end of the class discussion, they turned in either a printed or an electronic copy of the annotated paper.  

A series of questions that I used to guide the discussion are attached below as a Word document.  While I typically give out these types of discussion questions in advance and ask students to answer them prior to the discussion, in this case I did not.  The timing of this literature discussion immediately followed an exam, so I was just wanted to ensure that students had read the paper prior to our class discussion.  Making them turn in the annotated copy of the article was generally successful in achieving that outcome.

A second Word document is attached below containing the list of unfamiliar terms that were marked as unfamiliar by my students.  Most of these terms were highlighted by the majority of the class.  In some cases, I explained the meaning of the term in the course of our discussion, for example energy dispersive spectroscopy, but in other cases, the concepts were not central for a basic understanding of the paper and we never addressed them.  

 

Time Required: 
50 minutes

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