Thermodynamics, phase transitions and crystal structure of ammonium hexahalides: comparative study of the heat capacity and thermodynamic properties of (NH 4) 2PtCl 6, (ND4 ) 2PtCl 6, (NH 4)2 PtBr 6, (ND 4) 2PtBr6 , (NH 4) 2PdCl 6, (ND4 ) 2PdCl 6, (NH 4)2 TeCl 6, (ND 4) 2TeCl6 , and (NH 4) 2RuCl 6from 5 K to 350 K

2002 ◽  
Vol 34 (2) ◽  
pp. 133-153 ◽  
Author(s):  
Ron D. Weir ◽  
Edgar F. Westrum, Jr
Keyword(s):  
Crystal Structure ◽  
Heat Capacity ◽  
Phase Transitions ◽  
Thermodynamic Properties ◽  
Comparative Study

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

A note on the thermodynamic properties and infra-red spectra of sorbed water

1958 ◽  
Vol 247 (1251) ◽  
pp. 469-472 ◽  
Keyword(s):  
Crystal Structure ◽  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Exchangeable Cations ◽  
Synthetic Zeolite ◽  
Water Molecules ◽  
Sorbed Water ◽  
Infra Red ◽  
Cation Type ◽  
Anionic Framework

ce the fundamental basis of the heterogeneous nucleation of ice must lie in the ure of the interaction between water molecules and the nucleating solid and sidering the interest in the infra-red properties of water shown in this discusion it appears appropriate to make a preliminary comment on some of our ent studies on water-aluminosilicate systems. nvestigations are being made on the heat capacity, heats of sorption and a-red absorption spectra of water in the cages of a synthetic zeolite (Linde pe A) as a function of its water content. The crystal structure of this zeolite ed & Breck 1956) shows it to contain a system of cages bounded by six- mbered and eight-membered aluminosilicate rings. Each unit cell contains large, approximately spherical cavity, 11.4 Å in diameter, which can hold proximately 21 water molecules at saturation. The structure can be progres- sly dehydrated or rehydrated without causing lattice collapse, and thus we have, possibility of investigating the properties of a cluster of water molecules ying in size from 1 to 21 molecules. Furthermore, since exchangeable cations associated with the anionic lattice we can examine the influence on this sorbed ter of the change in cation type while retaining the anionic framework changed.

Crystal structure and thermodynamic properties of dinickel diphosphate dihydrate Ni2(H2O)2[P2O7]

2020 ◽  
Vol 49 (47) ◽  
pp. 17368-17374
Author(s):  
Galina V. Kiriukhina ◽  
Olga V. Yakubovich ◽  
Larisa V. Shvanskaya ◽  
Yevgeniy A. Ovchenkov ◽  
Anatoly S. Volkov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Thermodynamic Properties ◽  
Ground States ◽  
Spin Flip

The Ni member of the Me2(H2O)2[P2O7]2 family demonstrates antiferromagnetic ground states and sequences of spin–flip and spin–flop phase transitions.

Sign in / Sign up

Export Citation Format

Share Document