Small Temperature Dependence Of Thermal Expansion In Iron And Cobalt Based Amorphous Magnetic Material

2008 ◽  
Author(s):  
F. Alam ◽  
M. M. Kamal ◽  
M. A. Asgar ◽  
Amitabha Ghoshray ◽  
Bilwadal Bandyopadhyay
2017 ◽  
Vol 95 (11) ◽  
Author(s):  
Max Birkett ◽  
Christopher N. Savory ◽  
Angela N. Fioretti ◽  
Paul Thompson ◽  
Christopher A. Muryn ◽  
...  

1997 ◽  
Vol 196 (1) ◽  
pp. 205-209 ◽  
Author(s):  
Tetsur[obar] Nakamura ◽  
Pai-Hsuan Sun ◽  
Yue Jin Shan ◽  
Yoshiyuki Inaguma ◽  
Mitsuru Itoh ◽  
...  

1996 ◽  
Vol 60 (403) ◽  
pp. 963-972 ◽  
Author(s):  
Kevin S. Knight

AbstractThe thermal expansion tensor of crocoite has been determined from high-resolution neutron time-of-flight powder diffraction data. The temperature dependence of the lattice constants between 4.5 K and 290 K have been fitted to a quasi-harmonic Einstein model, and the temperature dependence of the thermal expansion tensor has been calculated for 60 K ≤ T ≤ 290 K. The magnitudes of the principal expansivities and their orientation exhibit saturation behaviour for temperatures above 300 K. The predicted saturated expansion coefficients are α11 = 33.1(1) × 10−6K−1, α22 = 15.72(3) × 10−6K−1, α33 = 3.36(1) × 10−6K−1, with α22 parallel to b and α11 lying at an angle of −37.86(5)° to c for the P21/n setting of the crystal structure. The direction of maximum expansion is approximately parallel to both and the least-squares line passing through the projection of the chromium atoms on (010). The direction of minimum expansion lies approximately parallel to [101]. No evidence was found for either a structural or magnetic phase transition between 4.5 K and 300 K.


2006 ◽  
Vol 955 ◽  
Author(s):  
Mark Holtz ◽  
D. Y. Song ◽  
S. A. Nikishin ◽  
V. Soukhoveev ◽  
A. Usikov ◽  
...  

ABSTRACTWe report studies of the temperature dependence of Raman lines in high quality GaN and AlN. The temperature dependence of the phonon energies and linewidths are used to produce consistent phonon decay properties of zone center optic phonons. In GaN we observe the E22 phonon to decay into three phonons, while the A1(LO) phonon is well described according to the so-called Ridley process – one TO and one LA phonon. For AlN the E22 phonon decays by two phonon emission and the A1(LO) line also exhibits a dependence consistent with the Ridley process. Along with the phonon decay processes, it is important in each case to take into account the contribution of the thermal expansion, including the temperature dependence, to describe observed temperature shifts in the phonon properties.


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