Investigation of the Thermal Properties of Solid CH3D at Very Low Temperatures

1975 ◽  
Vol 53 (22) ◽  
pp. 2546-2548 ◽  
Author(s):  
E. P. Jones ◽  
J. A. Morrison ◽  
E. L. Richards
Keyword(s):  
Heat Capacity ◽  
Low Temperatures ◽  
Spin Symmetry ◽  
Entropy Change ◽  
Total Conversion ◽  
Time Effects ◽  
Thermal Equilibration ◽  
Symmetry Species ◽  
Orientational Ordering ◽  
Heat Capacity Measurements

Heat capacity measurements have been performed on solid CH3D over the range 0.15 < T < 4 K where a large Schottky anomaly occurs. The entropy change in the anomaly is estimated to be 1.80 ± 0.10R which is about 14% less than that corresponding to complete orientational ordering of the molecules and total conversion of nuclear spin symmetry species. Some time effects associated with thermal equilibration have also been studied.

Heat Capacity Measurements on Small Samples at Low Temperatures

1972 ◽  
Vol 43 (2) ◽  
pp. 205-214 ◽  
Author(s):  
R. Bachmann ◽  
F. J. DiSalvo ◽  
T. H. Geballe ◽  
R. L. Greene ◽  
R. E. Howard ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Low Temperatures ◽  
Small Samples ◽  
Heat Capacity Measurements

A Calorimetric Study of Ammonium, Rubidium, and Potassium Hexafluophosphate

1963 ◽  
Vol 18 (2) ◽  
pp. 148-154 ◽  
Author(s):  
L. A. K. Staveley ◽  
N. R. Grey ◽  
M. J. Layzell
Keyword(s):  
Heat Capacity ◽  
Low Temperatures ◽  
Potassium Salt ◽  
Room Temperature ◽  
Entropy Change ◽  
Ammonium Ion ◽  
Calorimetric Study ◽  
First Order ◽  
Rubidium Salt ◽  
First Order Transition

Measurements have been made of the heat capacities of ammonium, rubidium, and potassium hexafluophosphate from ∼ 20°K to ∼ 300°K. The heat capacity curve of the ammonium salt shows two anomalous regions, and an order-disorder change also occurs in the rubidium salt. The potassium salt, however, undergoes a first-order transition with a large entropy change. The heat capacity of the ammonium and rubidium salts in the neighbourhood of room temperature (but not that of the potassium salt) is altered by cooling to low temperatures. In certain ranges of temperature it was unusually difficult with the rubidium salt to obtain reproducible heat capacity values. The results show that the rotation of the ammonium ion is not completely free, but they are consistent with almost free rotation in one degree of freedom and partially restricted rotation in the other two. The possible significance of the entropy changes of the various transitions is briefly discussed.

Cryogenic Magnetocaloric Effect in Distorted Double-perovskite Gd2ZnTiO6

2021 ◽  
Author(s):  
Ziyu Yang ◽  
Jun-Yi Ge ◽  
Shuangchen Ruan ◽  
Hongzhi Cui ◽  
Yu-Jia Zeng
Keyword(s):  
Heat Capacity ◽  
Magnetic Entropy Change ◽  
Mean Field ◽  
Double Perovskite ◽  
Entropy Change ◽  
Field Analysis ◽  
Magnetic Entropy ◽  
Static Magnetization ◽  
Magnetocaloric Properties ◽  
Heat Capacity Measurements

Herein, we report on the magnetic and magnetocaloric properties of a distorted double-perovskite, Gd2ZnTiO6, through static magnetization, heat capacity measurements, and mean-field analysis. The most pronounced isothermal magnetic entropy change...

Comparative Study of the Magnetocaloric Properties in Ni-Mn-X (X = Ga, In, Sn) by Magnetization and Specific Heat Measurements

2009 ◽  
Vol 1200 ◽  
Author(s):  
V V Khovaylo ◽  
K P Skokov ◽  
E V Avilova ◽  
Val Novosad ◽  
H Miki ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Ferromagnetic Shape Memory Alloys ◽  
First Order ◽  
Magnetocaloric Properties ◽  
Heat Capacity Measurements ◽  
Capacity Data ◽  
Ferromagnetic Shape Memory

AbstractSome compositions of Ni-Mn-X (X = Ga, In, Sn) ferromagnetic shape memory alloys exhibit a first order magnetostructural phase transition. Magnetic entropy change ΔSm in the vicinity of this transition has been studied by magnetization and heat capacity measurements. Comparison of these results point to a large difference in magnitudes of ΔSm obtained from magnetization and heat capacity data. It is suggested that this discrepancy originates from overestimation of \Delta S_m determined from the magnetization measurements and underestimation of ΔSm obtained from the heat capacity measurements.

The study of entropy change and magnetocaloric response in magnetic nanoparticles via heat capacity measurements

2018 ◽  
Vol 86 ◽  
pp. 107-112 ◽  
Author(s):  
Ondrej Kapusta ◽  
Adriana Zeleňáková ◽  
Pavol Hrubovčák ◽  
Róbert Tarasenko ◽  
Vladimír Zeleňák
Keyword(s):  
Heat Capacity ◽  
Magnetic Nanoparticles ◽  
Entropy Change ◽  
Heat Capacity Measurements

A low cost PC based card for heat-capacity measurements at low temperatures

Pramana ◽  
1995 ◽  
Vol 45 (1) ◽  
pp. 81-89 ◽  
Author(s):  
R S Sannabhadti ◽  
S Ramakrishnan ◽  
K Ghosh ◽  
Arun Patade ◽  
Girish Chandra
Keyword(s):  
Heat Capacity ◽  
Low Temperatures ◽  
Low Cost ◽  
Heat Capacity Measurements
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