Lecture - Intro to Crystallography

Quiz section for MSE 170: Fundamentals of Materials Science.
Recorded Summer 2020
There are some odd cuts in the lecture to protect students' identities.
Leave a comment if I got something wrong. Happy to receive feedback.
Checkout our undergraduate journal:
sites.google.com/uw.edu/urmse...

[@Oceanuniverse_.1]

I'm a Jordanian geology student from the University of Jordan, and I wanna thank you for the wonderful explanation of crystallography🤩✨️

[@neuraaquaria]

This is such a comprehensive introduction! Saved, thank you!

[@othmane8918]

bro called that introduction , thats literally my whole lecture thamks

[@hadiseesmaeili3031]

That was awesome. Thank you so much

[@apostleofazathoth7696]

Thank you for the lecture! I'm curious: besides bifringence, what optical properties do crystals have? Clarity, color and reflectivity come to mind but I wonder if there are more. Another question: besides simple recognition and measurement of angles is there a go-to method for determining the system of a crystal? Is there a relationship between refractive index and crystal system for systems other than cubic?

[@vogliofinireluniversita4558]

Great job

[@animadungdung3682]

Nice explanation

[@pkraja8723]

at around 30:35 , it was discussed that CsCl does NOT make a BCC lattice... [but is simple cubic] then what about CH4 (29:45)... why is it FCC [it has 2 different types of atoms... wouldnt it make it a simple cubic?] also thank you so much for this video!!

[@ZGNeale]

Hello Raja, This is a good question. CH4 is a molecule, and the molecule (of 5 atoms) can be translated to each of the lattice points in the fcc lattice. Each molecule is on a fcc lattice point with no other atoms elsewhere, so it has the FCC crystal structure. Many gases will arrange themselves into close-packed lattices (although not necessary cubic) because this is the lowest energy arrangement for Van der Waals solids. CsCl is an ionic solid, and can arrange in more interesting structures. The important point to make is that CsCl does not have the BCC crystal structure, and also does not have a BCC crystal lattice, it has the "Cesium Chloride" crystal structure. Other ionic compounds like CsBr and CsI also have the "Cesium Chloride" crystal structure, but CsF has the "Rock Salt / Halite" crystal structure like NaCl. Another way to look at it is that "crystal lattice" are points in space that define the symmetry of the crystal, and "crystal structure" is how the atoms arrange or molecules arrange on or near the lattice points.

[@pkraja8723]

@@ZGNeale thank you so much! this explained a lot :)

[@geoffgeoff143]

Ad note. Crystal glass and dishwashers dont mix.

[@ZGNeale]

Good to know, I hand wash my crystalware. Why shouldn't you use dishwashers? Is it the detergent or something else?

[@geoffgeoff143]

@@ZGNeale good boy. Never wash anything of any value in a dishwasher. The very alkaline detergents leach minerals out causing the glass to go milky. I'm Rusty on the exact chemical process.

[@dodo-js5gw]

Hello sir, thank you very much for this interesting course ! I was wonderring, is ice a crystal ?

[@ZGNeale]

Yes, ice is a good example of a crystal. The water molecules arrange themselves into a periodic structure. Do an image search of "snowflake microscope" and the crystal symmetry of ice will become apparent. Also, watch the first minute of my other lecture that introduces the different phases of ice: kzbin.info/www/bejne/eICkfZZppbt_nc0

[@geoffgeoff143]

Yes,ice is made from crystals but is it a mineral? Ice is the solid state of water, which of course has five states.

[@sabamacharadze8356]

@@geoffgeoff143 yes ice is mineral when it is in solid condition,but we know that often water is liquid so it is not mineral,so this is really complicated

[@joyinnocent2792]

@@geoffgeoff143 ice is not a mineral, go back and see d definition of minerals

[@joyinnocent2792]

@@sabamacharadze8356 ice is not a mineral, u can actually say it's crystalline buh it's no mineral

[@Xxvzqx999]

25:03 anyone else notice the ffc structure is the same as the kabbalah tree of life?

[@LaurentLaborde]

it's fun that i apparently know more than the students ^^

[@MrMusicanddedication]

Atoms and and the science of how crystals form weather it’s rain/snow/fire/air ctrl /admin absorbed info about fossils and crystals and how molecules and bonded together thank you 😘