I want to measure magnetic properties of HfO2 thin films deposited on Silicon wafer. I want to measure its magnetic properties, but I have no idea about its measurement.
HfO2 is a diamagnetic material with very small susceptibility.
NMR method, Guoy method, Faraday method are often used
for susceptibility measurements of such materials.
If small amount of material is available the Evans balance method
can be used for this purpose. For more details have a look:
https://www.unf.edu/~michael.lufaso/.../inorganic_lab_exp_8.pdf
Hello,
Hafnium(IV) oxide is the inorganic compound with the formula HfO2.
It is an electrical insulator with a band gap of 5.3~5.7 eV. It's quiet inert and adopts the same structure as zirconia (ZrO2).
3 crisatallographic structure are possible :
cubic Fm3m (a=b=c=5.3(Å)), quadratic P42/nmc , a=b=3.659 c=5.325) and monoclinic P21/c (a=5.117, b=5.175; c=5.291,β=99.220)
It is transparent for (UV) (λ>300 nm) and RI (≈10 μm).
Thin films of HfO2, used in modern semiconductor devices, are often deposited with an amorphous structure on silicium or aluminum, but al is paramagnetic!).
atomic Hf has the cofiguation 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d105p6 6s2 4f14 5d2 giving n=5, l=2 and m=-1 magnetic quantum number, so Hf would be magnetic with spin-orbite coupling and cristalline field interactions
Experimentally, it was reported that HfO2 is ferromagnetic with about 1 Bohr magneton par cell. This ferromagnetism is explained in the itinirent approaches (spin bands).These magnetic properties are very sensible to defects and symetry.
For maore details, see :
1. Pemmaraju C D et Sanvito S, « Ferromagnetism driven by intrinsic point defects in HfO2», Physical Review Letters, 94(21), 217205 (2005).
2. Bouzerar G et Ziman T, « Model for vacancy-induced d0 ferromagnetism in oxide
compounds», Physical Review Letters, 96(20), 207602 (2006)
Thanks Prof Jerzy Antoni Krupka, Ashwin and Mohamed El Hafidi for your answers.
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