scholarly journals Magnetic anisotropy energy of ferromagnetic shape memory alloys Ni2X(X=Fe, Co)Ga by first-principles calculations

AIP Advances ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 075001 ◽  
Author(s):  
Wangqiang He ◽  
Xingqiao Ma ◽  
Zhuhong Liu ◽  
Yi Wang ◽  
Long-Qing Chen
Keyword(s):  
Magnetic Anisotropy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
First Principles ◽  
Anisotropy Energy ◽  
First Principles Calculations ◽  
Ferromagnetic Shape Memory Alloys ◽  
Magnetic Anisotropy Energy ◽  
Ferromagnetic Shape Memory

Effects of Co Addition on Crystal Structure, Thermal Stability and Magnetic Properties of Ni-Mn-Ga Ferromagnetic Shape Memory Alloys from First-Principles Calculations

2012 ◽  
Vol 706-709 ◽  
pp. 1990-1995
Author(s):  
Jing Bai ◽  
Jean Marc Raulot ◽  
Yu Dong Zhang ◽  
Claude Esling ◽  
Xiang Zhao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Ferromagnetic Shape Memory Alloys ◽  
Electronic Density ◽  
Co Addition ◽  
Ferromagnetic Shape Memory

The effect of Co addition on the properties of Ni8-xMn4Ga4Cox(x=0, 0.5, 1, 1.5 and 2) ferromagnetic shape memory alloys are systematically investigated by means of the first–principles calculations within the framework of density functional theory (DFT) using the Viennaabinitiosoftware package (VASP). The formation energy results indicate that the added Co preferentially occupies the Ni sites in Ni2MnGa alloy. With the increase of the Co content, the optimized lattice parameters of the parent phase decreases regularly, whereas the lattice parameteraof the martensite increases andcdecreases, thus leading to a decrease of thec/aratio. The effects of Co addition on phase stability of the paramagnetic and ferromagnetic austenite are displayed. The difference in the magnetic properties in the investigated series can be explained from the electronic density of states analysis. The aim of this paper is to provide theoretical guidance for the development of new promising ferromagnetic shape memory alloys with optimized properties.

scholarly journals Temperature Dependence of Anisotropy in Ti and Gd Doped NiMnGa-Based Multifunctional Ferromagnetic Shape Memory Alloys

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2906
Author(s):  
Amadeusz Łaszcz ◽  
Mariusz Hasiak ◽  
Jerzy Kaleta
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Temperature Dependence ◽  
Magnetocrystalline Anisotropy ◽  
Anisotropy Constant ◽  
Anisotropy Energy ◽  
Ferromagnetic Shape Memory Alloys ◽  
Effective Anisotropy ◽  
Effective Anisotropy Constant ◽  
Ferromagnetic Shape Memory

The temperature dependence of magnetocrystalline anisotropy was investigated in detail for the polycrystalline Ni50Mn25Ga25, Ni50Mn25Ga20Ti5 and Ni50Mn25Ga20Gd5 ferromagnetic shape memory alloys in the temperature range of 50–400 K. The effective anisotropy constant was estimated from a series of high field magnetization curves based on the fitting procedure according to the law of approach to magnetic saturation. The low temperature martensitic phase was found to have a significantly higher anisotropy energy in comparison to a high temperature austenitic phase, which was observed through a sudden, distinct drop of anisotropy energy. The calculated values of the effective anisotropy constant were comparable to the results published by other authors. Moreover, the strong influence of chemical composition on the first-order phase transition and the second-order ferromagnetic to the paramagnetic transition was revealed. Finally, the strong coupling between the temperature dependence of the coercive field and the temperature dependence of magnetocrystalline anisotropy was also shown and discussed in the present study.

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