Effects of codoping on the ferromagnetic enhancement in ZnO

Abstract

The present work investigates the effect of the anionic co-doping on the magnetic properties of the DMSs doped with transition metal (TM) ions, namely that of Zn(Mn,X)O, X=C,N,P and S. The present findings are in complete analogy with the corresponding results for the cationic co-doping of Zn(TM1,TM2)O as studied in our earlier works. For both, the cationic and anionic co-dopings, we find that the magnetic impurities induce magnetic moments on their nearest neighbors with the largest induced magnetic moment observed on the cation or the anion which mediates two magnetic impurities. The magnetic interaction in the case of the anionic co-doping can be seen as a double exchange or a superexchange type of mechanism. On the other hand, in the cationic co-doping, the magnetic interactions take the form of a double-exchange or a superexchange between polarized tetrahedra each centered at one of the co-dopants.

Sintering characteristics and thermoelectric properties of Mn–Al co-doped ZnO ceramics

“…Previous studies have suggested that nanoscale phase separation or spinodal decomposition may occur in Mndoped 16) or MnAl co-doped ZnO. 17) Although, a ZT improvement due to these mechanisms was not observed in this study, other dopants could be identified which may undergo spinodal decomposition or nucleation and growth with the ZnO system.…”

“…First principles calculations also show that Mn has a tendency for clustering in ZnO and spinodal decomposition has been suggested to occur in MnAl co-doped ZnO. 16), 17) The presence of nanoscale phase-separated Mn-rich regions or spinodal decomposition could result in an additional decrease of the thermal conductivity. In addition, in contrast to previous studies where co-doping of Mg and Al was attempted to improve the ZT of ZnO, 13) the Mn dopant which has an electronegativity close to that of Zn has been studied.…”

Tunable magnetic properties of transition metal dopedMoS2

“…As demonstrated in our recent works, significant enhancement in the ferromagnetic coupling (FMC) among the magnetic dopants can be achieved for the diluted magnetic semiconductors (DMSs) and transition metal oxides (TMOs) by codoping [29,[33][34][35][36][37][38][39][40][41][42]. We attributed this enhancement to successive local spin-correlations of ferromagnetic type which act in opposition to the AFM superexchange coupling.…”

Raman scattering and electrical properties of Zn1−xMnxO films

“…might be ferromagnetic with Curie temperature (T C ) above room temperature (RT) [2,3], ZnO-based diluted magnetic semiconductors (DMSs) are attracting much more attention. This has led to a large number of experimental [4][5][6][7][8][9][10] and theoretical [11,12] studies of TM-doped ZnO. Specially, among all the TMs, the doping of Mn in ZnO is most encouraging because the ionic radius of Mn 2+ is similar to Zn 2+ and the substitutional Mn 2+ has the highest magnetic moment.…”