Magnetic interactions in spin-glasslikeGe1−x−ySnxMnyTe

Abstract

We investigated the nature of the magnetic phase transition in Ge 1−x−y Sn x Mn y Te mixed crystals with chemical composition changing in the range of 0.083Յ x Յ 0.142 and 0.012Յ y Յ 0.119. The dc magnetization measurements performed in magnetic fields up to 90 kOe and temperature range 2-200 K showed that the magnetic ordering at temperatures below T = 50 K exhibits features characteristic for both spin-glass and ferromagnetic phases. The modified Sherrington-Southern model was applied to explain the observed transition temperatures. The calculations showed that the spin-glass state is preferred in the range of the experimental carrier concentrations and Mn contents. The value of the Mn hole exchange integral was estimated to be J pd = 0.45Ϯ 0.05 eV. The experimental magnetization vs temperature curves were reproduced satisfactorily using the noninteracting spin-wave theory with the exchange constant J pd values consistent with those calculated using modified Sherrington-Southern model. The magnetization vs magnetic field curves showed nonsaturating behavior at magnetic fields B Ͻ 90 kOe indicating the presence of strong magnetic frustration in the system. The experimental results were reproduced theoretically with good accuracy using the molecular-fieldapproximation-based model of a disordered ferromagnet with long-range Ruderman-Kittel-Kasuya-Yosida interaction.

Anomalous Hall Effect in Ge1-x-yPbxMnyTe Composite System

“…Both constants are nearly temperature independent. Obtained parameters are similar to those reported in our former study of GeMnTe SnMnTe [4]. Taking into account the R H values estimated from the AHE analysis we obtain a corrected carrier concentration at temperatures below magnetic transition.…”

“…The calculated value indicates that the extrinsic skew scattering is a dominant mechanism responsible for AHE in studied Ge 0.743 Pb 0.183 Mn 0.074 Te crystal. The main role of this mechanism was also pointed out for bulk Ge 1−x−y Sn x Mn y Te crystals [4].…”

“…The nanocomposite crystals with clusters of magnetic impurities might lead to a further increase of T C , above 190 K. GePbMnTe mixed crystals create opportunity to control electric and magnetic properties independently [3]. Moreover, in GeTebased semimagnetic semiconductors the anomalous Hall eect has been observed [4,5]. This eect makes it possible to use the GeTe-based semimagnetic semiconductors for devices with electrically readable magnetic storage.…”

Phase-change control of ferromagnetism in GeTe-based phase change magnetic thin-films by pulsed laser deposition

“…It is the typical value for IV-VI DMSs. 22 The M(T) $ T 3/2 dependence and estimated exchange interaction J demonstrate that the crystalline Ge 0.98 Fe 0.02 Te film is a uniform long range ferromagnetic system. 23 Also note the conductivity from the upper inset of Fig.…”

First-Principles Study of the Structural, Electronic, Magnetic and Thermal Properties of the Cr Doped Ge6Mn2Te8 and Ge6Fe2Te8 Systems

“…Recently a large number of experimental studies related to the electronic structure [12][13][14], magnetism and magnetic transitions in several Ge-Te based alloys, such as Ge-Cr-Te, Ge-Mn-Te and Ge-Fe-Te have been reported [15][16][17]. In addition, there is a substantial amount of work on the DMS in general (please refer to Ref.…”