[formula omitted] electronic structure and spin EPR-shift of [formula omitted] ion in diluted magnetic p-type [formula omitted][formula omitted]

Abstract

In this correspondence, we deduce the non-parabolic band dispersion within the framework of effective mass representation (EMR) using k→⋅π→ perturbation theory in the presence of s.o interaction, magnetic impurity and external magnetic field. We measure the electronic parameters like Fermi energy, density of states, effective g factor and effective mass etc. in p-type Sn1−xEuxTe by taking into account a 6-level band structure with normal and bumped band edges. In the study, we use the experimental and simulated band gap values as functions of Eu+2 impurity and temperature. Apart from the general trend, the electronic parameters exhibit extreme behaviour near the band inversion point x=0.020 at T=300 K (Nayak et. al.2023), but in the range of impurity concentration and temperature considered; from x=0.0005 to x=0.001 and T=1.5 K to T=300 K, the behaviour is normal. Again, we follow the expression for spin-electron paramagnetic resonance (EPR) shift (Ps) where the perturbation expansion of Green’s function is used in the presence of the above-mentioned interactions. To get around the problem of loss of translational symmetry in the presence of the magnetic field, Green’s function is redefined in terms of Peierl’s phase factor. Here we have made an extensive study of the shift of Eu+2 ion in p-type Sn1−xEuxTe for several impurity concentrations from x=0.0005 to x=0.001 in the temperature range T=1.4 K to T=300 K. Lastly, we analyze the EPR shift and other electronic parameters and their anisotropies in p-type Sn1−xEuxTe as functions of carrier concentration and Eu impurity from T=1.5K to T=300K. We report the EPR shift is 2.97×10−3 at T=300 K and 3.31×10−3 at T=1.5 K with anisotropy at p=5×1020cm−3 in contrast to the experimental observation of +(3.4±0.4)×10−3 in the same system. The discrepancy is attributed to the reduction in the density of available states at Fermi energy at the L-band caused by the simultaneous rise in that at the Σ− band noticeable particularly at/above high hole concentrations p≥5×1020cm−3.