Title :
Effect of Pt Doping on B2-Phase Ordering Temperature of Co-Based Heusler Alloy: An Ab Initio Study
Author :
Zhao, B. ; Xu, X.G.
Author_Institution :
Sch. of Mater. Sci. & Eng., Univ. of Sci. & Technol., Beijing, China
Abstract :
In this paper, we propose a Pt-doping method to effectively decrease the phase transformation temperature of Co2FeAl0.5Si0.5 (CFAS) from A2 phase to B2 phase based on first-principle calculations. It has been demonstrated that the Pt atom tends to reside in the Si site to lower the system free energy. Meanwhile, the spin polarization can be reserved as 100% after Pt doping in a proper concentration less than 3.125%. Transition state search shows that the atomic diffusion barrier of Pt-doped CFAS is lower than that of the CFAS. Therefore, Pt doping in CFAS is a possible method to obtain ordered B2 phase at low annealing temperature.
Keywords :
ab initio calculations; aluminium alloys; annealing; cobalt alloys; diffusion; doping profiles; electron spin polarisation; free energy; iron alloys; platinum; silicon alloys; solid-state phase transformations; B2-phase ordering temperature; Co2FeAl0.5Si0.5:Pt; ab initio calculations; atomic diffusion; doping effect; first-principle calculations; free energy; low annealing temperature; phase transformation temperature; spin polarization; Annealing; Atomic measurements; Doping; Iron; Magnetic moments; Silicon; First-principles; Heusler alloy; first-principles; phase transformation temperature;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2015.2458333
