The A-site driven phase transition procedure of (Pb0.97La0.02)(Zr0.42Sn0.40Ti0.18)O3 ceramics: An evidence from electronic structure variation

AbstractThe crystal structure of a manganoan cummingtonite, composition [M4](Na0.13Ca0.41Mg0.46Mn1.00) [M1,2,3](Mg4.87Mn0.13)(Si8O22)(OH)2, (Z = 2), a = 9.5539(2) Å, b = 18.0293(3) Å, c = 5.2999(1) Å, β = 102.614(2)° from Talcville, New York, has been refined at high temperature using in situ neutron powder diffraction. The P21/m to C2/m phase transition, observed as spontaneous strains +ε1 = −ε2, occurs at ˜107°C. Long-range disordering between Mg2+ and Mn2+ on the M(4) and M(2) sites occurs above 550°C. Mn2+ occupies the M(4) and M(2) sites preferring M(4) with a site-preference energy of 24.6±1.5 kJ mol−1. Disordering induces an increase in XMnM2 and decrease in XMnM4 at elevated temperatures. Upon cooling, the ordered states of cation occupancy are ‘frozen in’ and strains in lattice parameters are maintained, suggesting that re-equilibration during cooling has not taken place.

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Effect of Zn doping on phase transition and electronic structures of Heusler-type Pd2Cr-based alloys: from normal to all-d-metal Heusler

RSC Advances ◽

10.1039/d0ra02951c ◽

2020 ◽

Vol 10 (30) ◽

pp. 17829-17835

Author(s):

Xiaotian Wang ◽

Mengxin Wu ◽

Tie Yang ◽

Rabah Khenata

Keyword(s):

Phase Transition ◽

Electronic Structure ◽

First Principles ◽

Electronic Structures ◽

Heusler Alloys ◽

First Principles Calculations ◽

Zn Doping

By first-principles calculations, for Heusler alloys Pd2CrZ (Z = Al, Ga, In, Tl, Si, Sn, P, As, Sb, Bi, Se, Te, Zn), the effect of Zn doping on their phase transition and electronic structure has been studied in this work.

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Magnetic Phase Transition in MnSi Based on the First Principle Calculations of Electronic Structure and Spin Fluctuation Theory

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.289.198 ◽

2019 ◽

Vol 289 ◽

pp. 198-204

Author(s):

Aleksandr Povzner ◽

Tatyana A. Nogovitsyna ◽

Arkadij G. Volkov ◽

Tagir Nuretdinov

Keyword(s):

Phase Transition ◽

Electronic Structure ◽

Magnetic Phase Transition ◽

Magnetic Phase ◽

Spin Fluctuation ◽

Fluctuation Theory ◽

Ministry Of Education ◽

Spin Correlations ◽

The Russian Federation ◽

Good Agreement

Based on the spin-fluctuation theory and LSDA + U + SO-calculations of the electronic structure, the spin states arising in the region of the magnetic phase transition in the helicoidal ferromagnet MnSi are studied. Within the framework of the stated model of the electronic structure, a temperature dependence of the homogeneous magnetic susceptibility is obtained near the temperature of the magnetic phase transition, which is in good agreement with experiment. At the temperature of the transition to the paramagnetic state, the left chirality vanishes, and spin correlations arise with a radius equal to the length of the spin helix, which then decreases with temperature. The results were obtained within the framework of the assignment of the Ministry of Education and Science of the Russian Federation, contract 3.9521.2017 / 8.9

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