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Offline vernii

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Anisotropy
« on: December 19, 2022, 12:03:56 PM »
What are the anisotropic conductivities in cadmium ?

Offline Enthalpy

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Re: Anisotropy
« Reply #1 on: December 21, 2022, 05:59:48 AM »
Hi vernii, welcome here!

Sadly enough, I didn't find them in the Handbook of Chemistry and Physics. Only one resistivity (68nΩ×m @273K), hence a mean value for a polycrystalline sample. Same at Wiki
https://en.wikipedia.org/wiki/Electrical_resistivities_of_the_elements_(data_page)
I had hoped to find anisotropic heat conductivities, but, nothing neither.

Though, the crystal being hexagonal close-packed, I can imagine the conductivity is anisotropic in monocrystalline cadmium. At least these people believe it
https://onlinelibrary.wiley.com/doi/abs/10.1002/pssb.2220480253 (only a computation)
https://pubs.rsc.org/en/content/articlelanding/2010/cp/b915967c
https://inis.iaea.org/search/search.aspx?orig_q=RN:7244118 measured
https://iopscience.iop.org/article/10.1088/0022-3735/10/8/012 measured
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.12.501
https://www.researchgate.net/publication/230929098_The_electrical_resistivity_anisotropy_of_Cd_Zn_and_Mg
All paywalled.
https://www.proquest.com/openview/25ddf6f074f159ebefd3ca7ae5d55174/1?pq-origsite=gscholar&cbl=18750&diss=y
I didn't find any single measured figure.

Offline vernii

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Re: Anisotropy
« Reply #2 on: December 22, 2022, 12:00:00 PM »
I read this on a website:-
For example in cadmium, it varies from 1.3 x 107 Sm-1 along the six-fold axis to 1.5 x 107 Sm-1 perpendicular to that axis.
https://eng.libretexts.org/Bookshelves/Materials_Science/TLP_Library_I/02%3A_Introduction_to_Anisotropy/2.05%3A_Anisotropic_electrical_conductivity

Whats exactly it to be like along six fold axis?

Offline Borek

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Re: Anisotropy
« Reply #3 on: December 23, 2022, 03:14:44 AM »
Whats exactly it to be like along six fold axis?

Have you tried to google the term?
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Offline Enthalpy

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Re: Anisotropy
« Reply #4 on: December 23, 2022, 10:52:04 AM »
Ouch, that's crystallography, for which I'm very weak.

I'd say 1.3×107S/m in the hexagonal plane of the HCP crystal and 1.5 in the direction perpendicular to it.

Offline vernii

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Re: Anisotropy
« Reply #5 on: December 24, 2022, 01:27:03 AM »
How will the axis along the plane will be six fold as six fold means on rotating at 60° the shape is maintained.

Offline Borek

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Re: Anisotropy
« Reply #6 on: December 24, 2022, 03:33:50 AM »
How will the axis along the plane will be six fold as six fold means on rotating at 60° the shape is maintained.

Have you tried to google it?

Such symmetries have very precise meaning in crystallography, you should be able to find the explanation without problems.
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Offline vernii

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Re: Anisotropy
« Reply #7 on: December 24, 2022, 10:11:37 AM »
I did not get it there thats why i have put the problem here.

Offline Borek

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Re: Anisotropy
« Reply #8 on: December 24, 2022, 11:59:44 AM »
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Offline vernii

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Re: Anisotropy
« Reply #9 on: December 24, 2022, 01:26:00 PM »
"The hexagonal unit cell is distinguished by the presence of a single line, called an axis of 6-fold symmetry, about which the cell can be rotated by either 60° or 120° without changing its appearance"..this is what i got from there which i already knew and the only axis that comes to my mind is the perpendicular axis passing from the middle.

Offline Borek

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Re: Anisotropy
« Reply #10 on: December 24, 2022, 07:35:49 PM »
the only axis that comes to my mind is the perpendicular axis passing from the middle.

That's exactly the one.
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