12.108  Structure of Earth Materials

Hi,

Here are some more tips on presentation and paper.

1. In order to figure out hkl, you need a "search-and-match" database which you may see at the X-ray facility at the CMSE when you had tutorial.  You may go there and use the database to figure out hkl.  However, there is an easier way if you prefer.  Go to "http://rruff.geo.arizona.edu/AMS/amcsd.php" and search your mineral.  It will show you bunch of literature data on your mineral.  Each dataset has a pdf file which shows detailed information on the used sample with experimental conditions.  Try to find a dataset which matches your mineral composition and experimental conditions best.  Then you click ""Download diffraction data" and it will show a table which shows two theta, d-spacing, intensity, and hkl.  Calculate d-spacing from your measured diffraction pattern and compare with the table value.  Then you can find hkl of your diffraction lines.  Try to use at least 5-10 diffraction lines.  Then from hkl and d-spacing using the equation we learned at a class will allow you to calculate unit-cell parameters.  If you want to use a software for this, google "UnitCell".

2. For atomic coordinate, you use the AM crystal structure database.  Take values from one that matches your sample best and draw crystal structure using "Balls and Sticks".  We used this software before.  Using the software, you can measure bond lengths and bond angles.

3. The most important thing to include for your presentation and paper are the data listed in the guideline I distributed long time ago.  Plus, your interpretation: try to link atomic scale crystal structure of your mineral to macroscopic properties of your mineral and compare minerals in your group and discuss why they are similar and why they are different.  For example, one of the most important difference between enstatite and amphibole is the single vs double chain, which I emphasized in the lecture.  You want to go back to your lecture note and try to find that is the most important subject for your mineral group.

If you have any other questions, please stop by my office (616) or email me.  Good luck.

Dan

Hi,

I uploaded a Zip file with all Raman data in it.  After decompress the file, you can see *.rxy files.  These are in ascii format, so that you can use them in Excel for plot.

Thanks.

Dan

Class-

You can pick up your lab quiz number 2 in my office.

-Mike

Hi,

As I announced in this morning we have an open UROP position (paid!) for this summer.  This is a position for independent research project on minerals at extreme conditions using the Raman spectroscopy system at my lab or the X-ray spectroscopy at synchrotron facility (either Advanced Photon Source, Chicago, or European Synchrotron Radiation Facility, Grenoble France).  One of our former UROP students published her result in a peer reviewed scientific journal as the first author and this is the purpose of our position!  We also sent her to the American Geophysical Union meeting at SF.  If you are interested in please contact me ASAP because the direct UROP funding proposal deadline is next Thursday. 

Thanks. 

Dan

We are looking for enthusiastic undergraduate students who will study the physical properties and structures of planetary materials (silicates, oxides, glasses) at extreme conditions (pressures of 100,000-1,000,000 bar and temperatures of 100-5,000 K) in order to understand the dynamic evolution of the Earth and planetary interiors.  The students will carry out independent research projects using Raman spectroscopy and X-ray diffraction. Two Raman spectroscopy systems are available at the high-pressure lab at EAPS (http://eaps.mit.edu/faculty/shim/index.html). X-ray diffraction measurements are performed at the synchrotron facilities, such as the Advanced Photon Source (http://www.aps.anl.gov).

We are seeking an UROP student who will carry out laser spectroscopy and X-ray diffraction measurements on planetary materials during summer 2008. The student will participate one or two synchrotron X-ray experiments (4 days per a trip) at the Advanced Photon Source (Argonne National Lab) or at the European Synchrotron Radiation Facility (Grenoble, France), and conduct Raman measurements at MIT.

Prerequi sites: Background in mineralogy, crystallography, solid state physics, or inorganic chemistry is a plus (12.108, 3.07, 3.072, 3.073, or 8.231).

Class-

The minerals are going to be put out for your perusal today, and will be left out until the lab quiz tomorrow at 2pm.

Noah and I will be running a review session tonight at 7pmish in the room if you have any questions.

-Mike