scholarly journals Исследование фазовых переходов в кристаллах (Cs,NH-=SUB=-4-=/SUB=-)-=SUB=-4-=/SUB=-(HSO-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=-(H-=SUB=-2-=/SUB=-PO-=SUB=-4-=/SUB=-)

2019 ◽  
Vol 61 (12) ◽  
pp. 2405
Author(s):  
Е.В. Селезнева ◽  
И.С. Тимаков ◽  
В.А. Коморников ◽  
В.В. Гребенев ◽  
О.Б. Зайнуллин ◽  
...  

The crystals of solid solution (NH4,Cs)4(HSO4)3(H2PO4) were investigate by synchronous thermal analysis and polarization microscopy methods at heating with the purpose of studying phase transitions in these solid solutions. The temperatures of structural modifications are established, and it is shown that the replacement of Cs cations by NH4 in Cs4(HSO4)3(H2PO4) crystals leads to a decrease in the temperature of phase transformations.

2020 ◽  
Vol 310 ◽  
pp. 6-13
Author(s):  
Vadim V. Efremov ◽  
Mikhail N. Palatnikov ◽  
Yuriy V. Radyush ◽  
Olga B. Shcherbina

Ferroelectric ceramic solid solutions LixNa1-xTayNb1-yO3 (х = 0.17; у = 0 – 0.5) with the perovskite structure have been obtained by the thermobaric synthesis method. Particularities of their microstructure, elastic properties, electrical conductivity and permittivity have been researched. It has been established that an increase in the thermobaric synthesis temperature leads to a decrease in the Young’s modulus value. Specific static conductivity values have been determined; charge carrier activation enthalpies На have been calculated. The Curie temperature of the samples has been determined to decrease with an increase in tantalum content. A Ferroelectric ceramic solid solution Li0.17Na0.83Ta0.1Nb0.9O3 was shown to undergo four structure phase transitions in the temperature range 300-820 К. A Li0.17Na0.83Ta0.1Nb0.9O3 has been shown to be a high temperature superionic. Possible mechanisms of the detected phenomena are discussed.


2012 ◽  
Vol 326-328 ◽  
pp. 573-577 ◽  
Author(s):  
Magdalena Jabłońska ◽  
Marta Mikuśkiewicz ◽  
Anna Śmiglewicz ◽  
E. Bernstock-Kopaczyńska

In this paper, phase transformation in alloys of the Al-Fe and Al-Fe-Cr systems was investigated. The alloys were prepared by melting and gravity casting. The studies of phase transformation were carried out on samples after casting and annealing, using the differential thermal analysis (DTA) and dilatometric method. The knowledge on the phase transformations in these alloys including the information about order-disorder transition is very important from the point of view of obtained mechanical and physical properties of alloys of the Al-Fe system. These results are an important contribution in development of knowledge on iron aluminides. In the article, temperatures of phase transformations connected with a change in order type and transition into disordered solid solution were defined. Conformity of the recorded DTA results and dilatometric analysis was achieved.


2020 ◽  
Vol 8 (17) ◽  
pp. 5795-5806
Author(s):  
Zenghui Liu ◽  
Yi Yuan ◽  
Zeng Luo ◽  
Hongyan Wan ◽  
Pan Gao ◽  
...  

Novel ferro-/piezoelectric solid solutions between bismuth-based perovskite and antiferroelectric material are designed and synthesized and their crystal structure, phase transitions, ferro-/piezoelectric properties and local polar structure are investigated.


2020 ◽  
Vol 5 (8(77)) ◽  
pp. 65-68
Author(s):  
Teymur Mammad Ilyasly ◽  
Rahman Hasanaga Fatullazade ◽  
Zakir Islam Ismailov ◽  
Nigar Nadir Jafarova

The synthesis of alloys of the system was carried out stepwise in rotary furnaces. The synthesis mode was selected based on the physicochemical properties of the elementary components. For homogenization, the alloys were subjected to isothermal annealing at 750 and 1275 K, depending on the Tm2Te3 concentration, for 250 h after homogenization of the alloys, they were subjected to physicochemical analysis. The results of differential thermal analysis showed that reversible thermal effects are observed in the alloys of the system. In alloys in a 1: 1 ratio, a new intermediate phase is formed with a composition corresponding to the TmAsTe3 compound. The homogeneity area is observed in the concentration range 52.5-47.5. It was found that in the concentration range 98.5-52.5 Tm2Te3 there are two phases - a mixture of β and of the solid solution, and in the concentration range of 47.51 mol% Tm2Te3 phases and α are in equilibrium. ) 66 The eutectic has coordinates of 11.5 mol Tm2Te3 at a temperature of 575 K.


Sign in / Sign up

Export Citation Format

Share Document