Magnetoresistance effect in anion-substituted manganese chalcogenides

Abstract

The electric and magnetic properties of anion‐substituted antiferromagnetic MnSe1−xTex (0.1 ≤ x ≤ 0.4) semiconductors in the 77–700 K temperature range and magnetic fields under 1 T are studied. In the MnSe1−xTex solid solutions, negative magnetoresistance in the vicinity of the Néel temperature for x = 0.1 and for composition with x = 0.2 in the paramagnetic range below 270 K is revealed. A dependence of the magnetic susceptibility versus the prehistory of the samples is found. The model of localized spin‐polarized electrons with the localization radius depending on the magnetic field is proposed for x = 0.1. In the paramagnetic range, the negative magnetoresistance and the behavior of magnetic moment are a result of orbital glass formation.

Influence of Induced Electrical Polarization on the Magnetoresistance and Magnetoimpedance in the Spin‐Disordered TmxMn1−xS Solid Solution

“…Theoretical calculations of the impedance by the formula (3,4)solid lines. (1,3,5,7,9) and in the field H ¼ 8 kOe (2,4,6,8,10) at T ¼ 300 K (1,2); 350 K (3,4); 400 K (5,6); 450 K (7,8); 550 K (9,10). Theoretical calculations of the impedance by the formula (3,4) À solid lines.…”

“…At high frequencies (Figure 15), the experimental data are well approximated by the Warburg linear impedance diagram [22,23] Figure 11. The frequency dependencies of the real (a) and imaginary (b) part of impedance for the sample Tm x Mn 1Àx S with x ¼ 0.1 measured in the zero magnetic field (1,3,5,7,9) and in the field H ¼ 8 kOe (2,4,6,8,10) at T ¼ 300 K (1,2); 350 K (3,4); 400 K (5,6); 450 K (7,8); 550 K (9,10). Theoretical calculations of the impedance by the formula (3,4)solid lines.…”

“…The colossal magnetoresistance in inhomogeneous semiconductors with the phase separation [1,2] and coexisting crystallographic phases [3] and polarons [4] has been intensively studied due to the possible use of these materials in spintronic devices, [5] sensors, and magnetic memory. [6,7] Along with the charge and spin, it is necessary to take into account the orbital degrees of freedom of electrons and effect of their orbital angular momenta on the kinetic properties of semiconductors [8,9] and formation of electronic phase transitions.…”

“…and in the field H ¼ 8 kOe(2,4,6,8,10) at T ¼ 300 K (1,2); 350 K (3,4); 400 K (5,6); 450 K (7,8); 500 K (9,10); 550 K (11) for the Tm x Mn 1Àx S samples withx ¼ 0.05 (a), x ¼ 0.1 (b), x ¼ 0.15 (c). Insert: The impedance hodographs at the magnetic fields H ¼ 0(7), H ¼ 8 kOe (8) at 450 K and at the zero magnetic field at 550 K(11).…”

Гальваномагнитные свойства поликристаллического селенида марганца Gd-=SUB=-0.2-=/SUB=-Mn-=SUB=-0.8-=/SUB=-Se

“…Уста-новлен рост диэлектрической проницаемости, а также магнитоемкостный эффект [5]. В селениде марганца при анионном замещении обнаружено отрицательное магнитосопротивление выше температуры Нееля до комнатных температур [6]. В связи с этим синтез нового халькогенидного соединения при катионном замещении марганца гадолинием в системе MnSe позволит выяс-нить влияние анионной системы в результате исследо-вания его транспортных и гальваномагнитных свойств с концентрацией в области протекания ионов гадолиния по решетке x = 0.2.…”