Rafal Michalski, Jakub Zygadlo
Spin and Orbital Moment compensation in SmAl2. Calculations Performed with ATOMIC MATTERS MFA Computation System.
SmAl2, RAl2, Laves Phase, CEF, MFA, MCE, spin-orbit coupling, Atomic Matters MFA
Crystals of SmAl2 exhibits unusual magnetic properties in comparison to other RAl2 (R: rare earth element), compounds reported by many authors [1-6]. Some experimental results like X-ray magnetic Compton scattering (MCS) , x-ray magnetic circular dichroism (XMCD) reveals the decomposition of total magnetization of Sm3+ ions in SmAl2 into spin and orbital contributions. We present the results of calculations of electronic and magnetic properties of SmAl2, performed with our new computation system called ATOMIC MATTERS MFA [7-9]. A localized electron approach was applied to describe the electronic structure evolution of Sm3+ ions over a wide temperature range and estimate Magnetocaloric Effect (MCE) of single crystals of SmAl2 under influence of external magnetic field applied along various directions of crystal. Magnetic and electronic properties of SmAl2 were calculated based on the fine electronic structure of the 4f 5 electronic configuration of the Sm3+ ions. Our calculations clearly confirms spin and orbital moment compensation. Our calculations yielded: magnetic moment value and direction; single-crystalline magnetization curves in zero field and in external magnetic field applied in various directions m(T,Bext); the 4f-electronic components of specific heat c4f(T,Bext); and temperature dependence of the magnetic entropy and isothermal entropy change with external magnetic field -?S(T,Bext). The cubic universal CEF parameters values used for definition of charge surrounding SmAl2 was estimated: A4=+15 Ka0 and A6 =-1.0 Ka0. These studies reveal the importance of multipolar charge interactions for successive descriptions an predictions thermomagnetic properties of real 4f electronic systems.
Cite this paper
Rafal Michalski, Jakub Zygadlo. (2017) Spin and Orbital Moment compensation in SmAl2. Calculations Performed with ATOMIC MATTERS MFA Computation System.. International Journal of Applied Physics, 2, 11-17