Magnetic phase transitions in the LiNi0.9 M 0.1PO4 (M = Mn, Co) single crystals

2022 ◽  
Author(s):  
Mikhail A. Semkin ◽  
Natalia V. Urusova ◽  
Anatoly I. Beskrovnyi ◽  
Aleksey Volegov ◽  
Alexander P. Nosov ◽  
...  
Keyword(s):  
Phase Transition ◽  
Heat Capacity ◽  
Neutron Diffraction ◽  
Single Crystals ◽  
Temperature Interval ◽  
Order Phase Transition ◽  
Magnetic Phase ◽  
Magnetic Phase Transitions ◽  
Magnetic Scattering ◽  
First Order Phase Transition

Abstract The LiNiPO4, LiNi0.9Mn0.1PO4, and LiNi0.9Co0.1PO4 single crystals are studied with heat capacity and neutron diffraction measurements over the temperature interval (10–30) K. Two peaks are observed on the temperature dependence of heat capacity for LiNiPO4, and LiNi0.9Co0.1PO4 samples. One peak indicates the first order phase transition from an antiferromagnetic commensurate (C) structure to an incommensurate (IC) one upon heating. According to neutron diffraction, in LiNiPO4 the IC ordering is described by the propagation vector k = 2π/b(0, 0.080, 0) at the Néel temperature T N = 20.8 K, and k = 2π/b(0, 0.098, 0) at T N = 20.2(1) K for LiNi0.9Co0.1PO4. A further increase in temperature leads to the second order phase transition to a paramagnetic state at critical temperature T IC = 21.7 K and 21.1 K for LiNiPO4 and LiNi0.9Co0.1PO4, respectively. The C and IC phases coexist over the temperature interval (20.6–20.8) K and (20.2–21.2) K in LiNiPO4 and LiNi0.9Co0.1PO4, respectively. In the LiNi0.9Mn0.1PO4 the magnetic phase transition occurs at T N = 22.7 K, but a magnetic scattering is observed up to 24.6 K.

scholarly journals First-Order Phase Transformation at Constant Volume: A Continuous Transition?

Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 31
Author(s):  
Víctor F. Correa ◽  
Facundo J. Castro
Keyword(s):  
Phase Transition ◽  
Heat Capacity ◽  
Order Phase Transition ◽  
Pressure Range ◽  
Constant Volume ◽  
Continuous Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
Temperature And Pressure ◽  
First Order Phase

We describe a first-order phase transition of a simple system in a process where the volume is kept constant. We show that, unlike what happens when the pressure is constant, (i) the transformation extends over a finite temperature (and pressure) range, (ii) each and every extensive potential (internal energy U, enthalpy H, Helmholtz energy F, and Gibbs energy G), and the entropy S is continuous across the transition, and (iii) the constant-volume heat capacity does not diverge during the transition and only exhibits discrete jumps. These non-intuitive results highlight the importance of controlling the correct variables in order to distinguish between continuous and discontinuous transitions. We apply our results to describe the transition between ice VI and liquid water using thermodynamic information available in the literature and also to show that a first-order phase transition driven in isochoric condition can be used as the operating principle of a mechanical actuator.

scholarly journals Magnetic phase transitions in Eu( Co1−xNix)2−yAs2 single crystals

2020 ◽  
Vol 4 (8) ◽  
Author(s):  
N. S. Sangeetha ◽  
Santanu Pakhira ◽  
D. H. Ryan ◽  
V. Smetana ◽  
A.-V. Mudring ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Single Crystals ◽  
Magnetic Phase ◽  
Magnetic Phase Transitions

scholarly journals Gravitational wave signals of dark matter freeze-out

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Danny Marfatia ◽  
Po-Yan Tseng
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Gravitational Waves ◽  
Order Phase Transition ◽  
First Order ◽  
Stochastic Background ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
First Order Phase ◽  
Freeze Out

Abstract We study the stochastic background of gravitational waves which accompany the sudden freeze-out of dark matter triggered by a cosmological first order phase transition that endows dark matter with mass. We consider models that produce the measured dark matter relic abundance via (1) bubble filtering, and (2) inflation and reheating, and show that gravitational waves from these mechanisms are detectable at future interferometers.

Discovering a First-Order Phase Transition in the Li–CeO2 System

Nano Letters ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 1282-1288 ◽  
Author(s):  
Kaikai Li ◽  
Xiaoye Zhou ◽  
Anmin Nie ◽  
Sheng Sun ◽  
Yan-Bing He ◽  
...  
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase
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