Electronic and magnetic properties of some ii iv v2 and I iii vi2 type chalcopyrites a first principles study

Abstract

In this thesis work, the structural, electronic and magnetic properties of some II-IV-V2 (ZnMX2 and CdMX2; M = Sc, Ti, V, Cr, Mn, Fe; X = P, As) and I-III-VI2 (CuMY2 and AgMY2; M = Sc, Ti, V, Cr, Mn, Fe; Y = S, Se) compounds in the chalcopyrite crystal structure were calculated. To be more general AII(I)BIV(III)CV(VI)2 (A = Zn, Cd / Cu, Ag; B = Ge / Ga; C = P, As / S, Se) compounds are studied with the substitution of M (M = Sc, Ti, V, Cr, Mn, Fe) atoms at B site. Goal of this study is to predict the HMF property in these systems and to investigate whether the HM is preserved in the chalcopyrite crystal structure. FP-LAPW method is used for the calculation within GGA and LSDA under WIEN2k code. newlineAII(I)BIV(III)CV(VI)2 compounds are found to exist in ordered body-centered tetragonal (BCT) chalcopyrite structure, disordered zinc-blende (ZB) structure and cubic L21 structure. Total energy vs. volume calculations were performed for the above mentioned compounds in three different structures in order to find the stable crystal structure. Among the three different crystal structure the minimum energy as a function of relative volume was observed for the BCT chalcopyrite crystal structure. Hence, further non-spin-polarized (NM) and spin-polarized (FM and AFM) calculations are performed in the BCT chalcopyrite crystal structure for the ZnMX2 compounds. Following them, non-spin-polarized and spin-polarized calculations of CdMX2, CuMY2 and AgMY2 compounds are performed in the BCT chalcopyrite crystal structure. newline newline