Thermodynamics of ammonium haloplatinates IV. Heat capacity, phase transitions, and thermodynamic properties of (NH4)2PtBr6fromT=6 K toT=320 K

1998 ◽  
Vol 30 (12) ◽  
pp. 1483-1493 ◽  
Author(s):  
Jane E. Callanan ◽  
Ron D. Weir ◽  
Edgar F. Westrum, Jr.
Keyword(s):  
Heat Capacity ◽  
Phase Transitions ◽  
Thermodynamic Properties

scholarly journals SYNTHESIS AND STUDY OF THERMODYNAMIC PROPERTIES OF NEW ZINCATE-MANGANITES NdM2IIZnMnO6 (MII − Mg, Ca)

2018 ◽  
Vol 61 (3) ◽  
pp. 16
Author(s):  
Bulat К. Kasenov ◽  
Shuga B. Kasenova ◽  
Zhenisgul I. Sagintaeva ◽  
Yerbolat Y. Kuanyshbekov ◽  
Meruert O. Turtubaeva
Keyword(s):  
Heat Capacity ◽  
Phase Transitions ◽  
Thermodynamic Properties ◽  
Temperature Dependence ◽  
Ceramic Technology ◽  
Cell Parameters ◽  
Dynamic Calorimetry ◽  
Temperature Dependences ◽  
Calorimetric Studies ◽  
Experimental Values

Zincate-manganites with the composition NdM2IIZnMnO6 (MII− Mg, Ca) were synthesized using ceramic technology from oxides of Nd (III), Zn (II), Mn (III) and carbonates of alkaline-earth metals - magnesium and calcium. X-ray patterns of the prepared substancies were measured on a DRON-2.0 diffractometer. We established that they crystallize in the cubic system with the following unit cell parameters: NdMg2ZnMnO6 – а=13.927±0.035 Å, Z = 4, V0 = 2701.36±0.11 Å3, V0el.cell. = 675.34±0.03 Å3, ρX-ray = 4.20, ρpycn. = 4.19±0.01 g/cm3; NdCa2ZnMnO6 – а=13.910±0.030 Å, Z = 4, V0 = 2691.45±0.10 Å3, V0el.cell. = 672.86±0.03 Å3, ρX-ray = 4.04, ρpycn. = 4.01±0.08 g/сm3. The temperature dependence of the heat capacity of NdMg2ZnMnO6 and NdCa2ZnMnO6 was studied by dynamic calorimetry in the range of 298.15-673 K on the IT-S-400 calorimeter. Five parallel experiments were performed at each temperature point with 25 K step. The results were averaged and analyzed using mathematical statistics. As a result of calorimetric studies of the heat capacity, within the temperature range of 298.15-673 K, we discovered on the curves of the temperature dependence of heat capacity the phase transitions of the II kind at the following temperatures: 373, 548 К- NdMg2ZnMnO6, 448, 573 К – NdCa2ZnMnO6. These phase transitions were probably due to Schottky effects -the transition from semiconductivity to metallic conductivity, and variations in capacity, dielectric permittivity, the occurrence of Curie or Neel points. The equations of the temperature dependence of the heat capacity were derived on the basis of the experimental values with account the temperatures of the phase transitions. By the ion increment method, we calculated the standard entropies of the compounds investigated. We calculated the temperature dependences of С°р(Т) and thermodynamic functions Н°(Т)-Н°(298.15), S°(T) and Фхх(Т).Forcitation:Kasenov B.K., Kasenova Sh.B., Sagintaeva Zh.I., Kuanyshbekov Е.Е., Turtubaeva М.О. Synthesis and study of thermodynamic properties of new zincate-manganites NdM2IIZnMnO6 (MII − Mg, Ca). Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 16-20

Heat capacity at constant pressure and thermodynamic properties of phase transitions in PbMO3 (M=Ti, Zr and Hf)

2009 ◽  
Vol 95 (2) ◽  
pp. 675-683 ◽  
Author(s):  
T. Yoshida ◽  
Y. Moriya ◽  
T. Tojo ◽  
H. Kawaji ◽  
T. Atake ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Phase Transitions ◽  
Thermodynamic Properties ◽  
Constant Pressure

scholarly journals Heat capacity and thermodynamic properties of ditungsten carbide, W2C1−x, from 10 to 1000 K

1988 ◽  
Vol 129 (1) ◽  
pp. 115-125 ◽  
Author(s):  
F. Grønvold ◽  
S. Stølen ◽  
E.F. Westrum ◽  
A.K. Labban ◽  
B. Uhrenius
Keyword(s):  
Heat Capacity ◽  
Thermodynamic Properties

Low-temperature heat capacity and thermodynamic properties of endo-Tricyclo[5.2.1.02,6]decane

2003 ◽  
Vol 35 (12) ◽  
pp. 1897-1903 ◽  
Author(s):  
Li-Guo Kong ◽  
Zhi-Cheng Tan ◽  
Jie Xu ◽  
Shuang-He Meng ◽  
Xin-He Bao
Keyword(s):  
Heat Capacity ◽  
Low Temperature ◽  
Thermodynamic Properties ◽  
Temperature Heat ◽  
Low Temperature Heat Capacity
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