Preparation and Magnetic Properties of LaMnO₃₊δ (0≤ δ ≤0.154)

The structural, electrical, and magnetic properties of ceramic perovskite manganites LaMnO₃₊δ (δ = 0-0.154) are investigated. It is found that, in a weak magnetic field ( B = 2 G), the LaMnO₃₊δ manganite with δ= 0.065 at temperatures below the Curie temperature Tс of the paramagnet -ferromagnet phase transition has a mixed (spin glass + ferromagnet) phase. In LaMnO₃₊δ manganites with the parameter δ = 0.100-0.154, this phase transforms into a frustrated ferromagnetic phase. A similar transformation was observed previously in La₁₋ₓ CaₓMnO₃ сompounds at calcium contents in the range 0 ≤ x ≤ 0.3yesBelgorod State Universit

Unconventional critical behavior of magnetic susceptibility as a consequence of phase separation and cluster formation in La₀.₇Ca₀.₃MnO₃ thin films

Nonuniversal critical behavior of the dc magnetic susceptibility is observed near the paramagnetic to ferromagnetic transition in La₀.₇Ca₀.₃MnO₃ film samplesyesBelgorod State Universit

Hopping conductivity of Ni-doped p-CdSb in strong magnetic fields

In this work detailed investigation of the hopping conductivity in p-CdSb:Ni in strong magnetic field is reported to complete the picture of hopping charge transfer in this materialyesBelgorod State Universit

Variable-range hopping conductivity in La₁₋xCaxMn₁₋yFeyO₃: evidence of a complex gap in density of states near the Fermi level

The resistivity, ρ, of ceramic La₁₋xCaxMn₁₋yFeyO₃ with x = 0.3 and y = 0.0–0.09 is found to obey, between a temperature Tv ≈ 310–330 K and the ferromagnetic-to-paramagnetic transition temperature, Tc = 259–119 K (decreasing with y), the Shklovskii–Efros-type variable-range hopping conductivity law, ρ(T) = ρ₀(T) exp[(T₀/T)¹/₂]. This behaviour is governed by generation of a soft Coulomb gap Δ ≈ 0.42 eV in the density of localized states and a rigid gap δ(T) ≈ δ(Tv)(T/Tv)1/2 with δ(Tv) ≈ 0.16, 0.13 and 0.12 eV at y = 0.03, 0.07 and 0.09, respectively. Deviations from the square root dependence of δ(T), decreasing when y is increased, are observed as T → TC. The prefactor of the resistivity follows the law ρ₀ (T) ~ Tm, where m changes from 9/2 at y = 0 to 5/2 in the investigated samples with y = 0.03, 0.07 and 0.09, which is connected to introduction of an additional fluctuating short-range potential by doping with FeyesBelgorod State Universit

Magnetization and Shubnikov-de Haas effect in diluted magnetic semiconductors (Cd₁₋x₋yZnxMny)₃As₂

Presents the results of the Shubnikov-de Haas (SdH) effect and magnetization of single crystals of (Cd1-x-yZnxMny)3As2 magnetic semiconductors. Analysis of SdH oscillations; Exchange constant in the conduction band and spin-dependent part of the Dingle temperatureyesBelgorod State Universit

Silicon carbide nanolayers as a solar cell constituent

Thin films of predominantly amorphous n-type SiC were prepared by non-reactive magnetron sputtering in an Ar atmosphere. A previously synthesized SiC was used as a solidstate target. Deposition was carried out on a cold substrate of ptype Si (100) with a resistivity of 2Ωcm. The Raman spectrum shows a dominant band at 982 cm-¹, i.e., in the spectral region characteristic for SiC. It was found that the root mean squareroughness varies from about 0.3 nm to 9.0 nm when the film thickness changes from about 2 nm to 56 nm, respectively. Transmission electron microscopy studies showed that SiC thin films consist predominantly of an amorphous phase with inclusions of very fine nanocrystallites. A heterostructure consisting of a p-type Si (100) and a layer of predominantly amorphous n-type SiC was fabricated and studie

The Hall effect in Ni-doped p-CdSb in a strong magnetic field

The Hall effect in single crystals of the group II–V semiconductor p-CdSb doped with 2 at% of Ni is investigated between T = 1.5 and 300 K in pulsed magnetic fields up to B = 25 T. The Hall resistivity, ρH, exhibits a nonlinear dependence on B, which is strongly pronounced below ~10 K but is still observed even up to 300 KyesBelgorod State Universit

Magnetic properties of the new diluted magnetic semiconductor Zn₁₋ₓMnₓAs₂: evidence of MnAs clusters

The preparation and magnetic properties of the diluted magnetic semiconductor Zn₁₋ₓMnₓAs₂, opening a novel group of II–V₂ compounds alloyed with transition metal elements, are reported for the first timeyesBelgorod State Universit

Variable-range hopping conductivity of La₁₋xSrxMn₁₋yFeyO₃

The temperature dependence of the resistivity,ρ, of ceramic of La₁₋xSrxMn₁₋yFeyO₃ (LSMFO) samples with x=0.3 and y=0.03, 0.15, 0.20 and 0.25 (or simply #03, #15, #20 and #25, respectively) is investigated between temperaturesT∼5 and 310 K in magnetic fields B up to 8 TyesBelgorod State Universit

Asymmetry and parity violation in magnetoresistance of magnetic diluted Dirac-Weyl semimetal (Cd0.6Zn0.36Mn0.04)3As2

The effective mass of electrons extracted from SdH oscillations analysis is found to be orientation dependent. Smeared kinks correlated with the SdH oscillations are also observed in the Hall effect study for orientation (1). Magnetoresistance peculiarities can be related to specific properties of the Dirac semimetals and their evolution under magnetic fiel