@article{afc9abbe94ad438b8dd1adb656291527,
title = "Magnetic interactions in diluted magnetic semiconductors",
abstract = "We summarize the results of recent calculations of Mn-Mn d-d exchange in II1-xMnxVI alloys. The dominant interaction is antiferromagnetic superexchange. A novel procedure for obtaining sp-d exchange constants from ferromagnetic band calculation is presented. The results support earlier qualitative pictures and are in substantial agreement with experiment.",
author = "Hass, {K. C.} and Larson, {B. E.} and H. Ehrenreich and Carlsson, {A. E.}",
note = "Funding Information: ence to ensure the presence of a finite magnetization and associated spin splittings. (Note that J&{\textquoteleft}, and ./,:_, cannot be determined from band calculations for antiferromagnetic ordering since (S:). AE, and AE, are then all zero.) The resulting exchange constants for zb MnTe are listed in table 1 along with similar results for zb MnSe. In both cases we find J,kmd> 0 (ferromagnetic), J,k_, < 0 and 1J ,k_,, 1/ 1J ,;_d 1 z=3-. These qualitative features are believed to be characteristic of all II, _,Mn,VI DMS. Their physical origin was explained previously [X] in terms of the different symmetry character of the conduction and valence band edges and can be easily understood from fig. 1. J,i_, is dominated by a large antiferromagnetic contribution which results from an appreciable d admixture at the top of the valence band. This strong hybridization is apparent in the figure as a repulsion between the r,s valence states and the Mn d levels. A similar hybridization is forbidden for the r, conduction band minimum by symmetry. The only con- tribution to J,>_d is thus direct potential exchange. which is smaller in magnitude than J$!, cl and of opposite sign. Although the present calculations are strictly valid only for .\-= 1, we compare our results in table 1 with experimental J\:“<, values [7] for DMS with relatively low Mn concentrations (I = 0.1~0.3).S ince the position of the Mn d-levels is roughly independent of \. the same would be expected for .$C, and J,kmC,.( {\textquoteleft}on-centration variations of about 0.3 result experimentally in only small changes [6]. The ASW results in table I agree quite well with experiments for Cd and Zn auh-stituted alloys. They further predict the observed trend that / J,imc,I is larger in Se-than Te-based DMS. an effect again resulting from stronger Mn d-anion p hybridization. We would hke to thank A.R. Williams for maklng the ASW code developed at IBM availahlc to us. Thiz work was supported in part by the Joint Services Hec-tronics Program (Contract no. N00014-X4-K-0465). the National Science Foundation (Predoctoral Fellowship (for B.E.L.) and Grant no. DMRX2-07431 ) and (for A.E.C.) the Department of Energy (Grant no. DE-FG02-X4-ER45130).",
year = "1986",
month = feb,
doi = "10.1016/0304-8853(86)90819-X",
language = "English",
volume = "54-57",
pages = "1283--1284",
journal = "Journal of Magnetism and Magnetic Materials",
issn = "0304-8853",
number = "PART 3",
}