The Role of Frustration in Magnetism of Ge_1-xCr_xTe Semimagnetic Semiconductor

Abstract

We present preliminary studies of magnetic properties of Ge 1−x Cr x Te semimagnetic semiconductors with low chromium content x < 0.026. The static and dynamic magnetometry techniques were employed for the current investigations. The obtained results showed large bifurcations between zero-field cooled and field cooled magnetization curves at temperatures lower than 50 K. The dynamic susceptibility measurements proved via frequency shifting of the peaks that the observed magnetic order at low temperatures was the spin-glass-like state caused by magnetic frustration of the system.

Spinodal Decomposition of Magnetic Ions in Eu-Codoped Ge1-xCrxTe

“…the magnetic properties of the Ge 1−x−y Cr x Eu y Te alloy. Here we continue our previous investigations devoted to Ge 1−x Cr x Te alloy showing spin-glass and ferromagnetic order at T < 60 K (see [7] and [8]). In the present work we show that irrespective of the average Cr content, the Curie temperature can be stabilized by the average Eu content.…”

“…Thus, GeTe based diluted magnetic semiconductors are perceived as potential material for the semiconductor spintronics working at room temperature. In contrast to thin layers, bulk Ge 1−x Cr x Te crystals show much lower transition temperatures, T ≤ 60 K, with the presence of both ferromagnetic and spin-glass-like states [7,8]. The nature of this decrease of the magnetic ordering temperature remains an unexplained issue.…”

Magnetic Interactions in Ge/1-x/Cr/x/Te Semimagnetic Semiconductors

“…curves for the samples with low chromium content, x < 0.03, showed a broad peak with a maximum at temperatures lower than 35 K. Peaks in the ac susceptibility shifted with frequency, as reported in Ref. 16, and were convincingly identified as the appearance of a spin-glass freezing for x < 0.03. However, a qualitatively different shape of the Re(χ AC (T))…”

“…The present work extends our preliminary studies (see Ref. 16) of low Cr-content Ge 1-x Cr x Te samples with x ≤ 0.025 into higher Cr composition 0.035 ≤ x ≤ 0.061, in which the magnetic order changed dramatically from a spin-glass freezing into ferromagnetic align- The experimental results are analyzed within the model based on spin waves theory. The theoretical results are able to reproduce the observed magnetic properties of the alloy for…”

Magnetic properties of Sn/1-x/Cr/x/Te diluted magnetic semiconductors

“…2 Chromium alloyed GeTe also shows transition temperatures as high as 160 K for thin layers 3 and 60 K for bulk crystals. [4][5][6] Eggenkamp et al investigated magnetic properties of Sn 1-x Mn x Te and found the Curie-Weiss temperature ranging from 3 K up to 16 K for Mncontent, x, changing from 0.03 to 0.1, respectively. 7 They found the Mn-hole exchange constant for Sn 1-x Mn x Te equal to 0.1 eV.…”