Magnetic properties of compacted ${\text{La}}_{0.8}{\text{Ca}}_{0.2}{\text{MnO}}_{3}$ manganite nanoparticles with average particle size 18 and 70 nm Curie temperatures ${T}_{\text{C}}\ensuremath{\approx}231\text{ }\text{K}$ ${T}_{\text{C}}\ensuremath{\approx}261\text{ }\text{K}$, respectively, have been investigated. The relative volume the ferromagnetic phase has estimated to be 52% for ensembles particles 92% particles. It was found that applied hydrostatic pressure enhances...

The influence of dc current flow on the resistivity and phase transitions in low-doped ${\mathrm{La}}_{0.82}{\mathrm{Ca}}_{0.18}{\mathrm{MnO}}_{3}$ single crystals has been investigated. At low temperatures, where strongly increases with decreasing temperature, depresses a way consistent domination tunneling-conduction mechanisms. Current exceeding some threshold currents results switching metastability. Bipolar sweep both positive negative direction creates low-resistivity states sample....

An exchange-bias (EB) effect observed in single crystal $\mathrm{ErFe}{\mathrm{O}}_{3}$ compensated ferrimagnet, exhibiting the EB field ${H}_{\mathrm{EB}}$ increasing and diverging upon approaching compensation temperature ${T}_{\mathrm{comp}}=45\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, changing sign with crossing ${T}_{\mathrm{comp}}$, is reported. The may be changed to opposite one by varying field-cooling protocol, depending on whether ${T}_{\mathrm{comp}}$ crossed decreasing or...

Measurements of electrical resistance, magnetization, ac magnetic susceptibility, and ferromagnetic resonance ${\mathrm{La}}_{0.82}{\mathrm{Ca}}_{0.18}{\mathrm{MnO}}_{3}$ single crystal were carried out at temperatures below above the Curie temperature, ${T}_{C}=180\ifmmode\pm\else\textpm\fi{}1\mathrm{K}.$ A state mixed phases, metallic insulating, is clearly evident from measurements electron resonance, ${T}_{C}.$ The effect applied hydrostatic pressure P field H on resistive properties...

Magnetic properties of electron-doped ${\text{La}}_{0.2}{\text{Ca}}_{0.8}{\text{MnO}}_{3}$ manganite nanoparticles with average particle size ranging from 15 to 37 nm, prepared by the glycine-nitrate method, have been investigated in temperature range 5--300 K and magnetic fields up 90 kOe. A monotonous enhancement weak ferromagnetism linked reduction was observed for all nanoparticles. hysteresis loops also indicate size-dependent exchange bias effect displayed horizontal vertical shifts...

Magnetic properties of compacted $50\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ ${\mathrm{CaMnO}}_{3\ensuremath{-}\ensuremath{\delta}}$ (CMO) nanoparticles have been investigated. Measurements ac-susceptibility exhibit upon cooling two magnetic transitions at $T\ensuremath{\sim}270\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ accompanied by a small spontaneous moment and para-antiferromagnetic (AFM) transition ${T}_{\text{N}}\ensuremath{\sim}120\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, observed...

The unconventional exchange-bias (EB) effect in single crystals of $R\mathrm{Fe}{\mathrm{O}}_{3}(R=\mathrm{Nd},\phantom{\rule{0.28em}{0ex}}\mathrm{Sm})$ compensated ferrimagnets (fMs), composed two antiferromagnetically (AFM) coupled $R$ and Fe sublattices with opposite ferromagnetic (FM) moments, exhibiting the FM moment reversal via a fast spin switching is reported. In ${\mathrm{NdFeO}}_{3}$, EB anisotropy field emerges diverges upon approaching compensation temperature...

The resistivity of La0.82Ca0.18MnO3 single crystal has been investigated as a function external magnetic field and separately under an applied current flow. measurements were carried out at various temperatures below above the ferromagnetic transition temperature TC. It found that dynamic electroresistance exhibits stunning similarities to colossal magnetoresistance corresponding temperatures. correlation observed between electric- magnetic-field effects is attributed electrically induced...

Transport, magnetic, and thermal properties of phase-separated ${\mathrm{La}}_{0.8}{\mathrm{Ca}}_{0.2}\mathrm{Mn}{\mathrm{O}}_{3}$ crystal were studied in a wide temperature range down to $10\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. At low temperatures below the Curie point ${T}_{C}=184\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, sample resistance is characterized by spontaneous transitions higher resistivity metastable states. Metastability becomes more pronounced when enforced application current...

The exchange-bias (EB) effect with sign reversal was found in $\mathrm{LuF}{\mathrm{e}}_{0.5}\mathrm{C}{\mathrm{r}}_{0.5}{\mathrm{O}}_{3}$ ferrite-chromite, which is a weak ferrimagnet below ${T}_{\mathrm{N}}=265\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, exhibiting antiparallel orientation of the ferromagnetic (FM) moments Fe and Cr sublattices due to opposite Fe-Cr Dzyaloshinskii vector, as compared that Fe-Fe Cr-Cr. FM studied compound compensate each other at temperature...

Ferromagnetic and transport properties of ${\mathrm{La}}_{0.8}{\mathrm{Ca}}_{0.2}{\mathrm{MnO}}_{3}$ ${\mathrm{La}}_{0.78}{\mathrm{Ca}}_{0.22}{\mathrm{MnO}}_{3}$ single crystals were studied in temperature range $4.2\mathrm{K}<T<300\mathrm{K}$ under hydrostatic pressure up to 12 kbar. It was found that the above compounds exhibit different shifts Curie temperatures ${T}_{C}$ pressure. For ${\mathrm{dT}}_{C}/dP\ensuremath{\approx}0.3\mathrm{K}/\mathrm{k}\mathrm{b}\mathrm{a}\mathrm{r},$...

The magnetic properties of nanocrystalline manganites La1−xMnO3+δ with particle size 20 (LMO20), 25 (LMO25), and 30 nm (LMO30), prepared by the citrate method, have been investigated in temperature range 5–320 K, field up to 90 kOe under quasi-hydrostatic pressures 14.5 kbar. studies involve sequential zero-field-cooled magnetization (M) measurements followed during cooling same (H) complementary ac susceptibility. Additional M versus H were carried out at ambient applied pressures. All...

Magnetic properties of nanocrystalline ${\text{LaCoO}}_{3}$ with particle size 25, 30, 32, and 38 nm, prepared by the citrate method, were investigated in temperature range 2--320 K, magnetic field up to 50 kOe, under hydrostatic pressure 11 kbar. All nanoparticles exhibit weak ferromagnetism below ${T}_{C}\ensuremath{\approx}85\text{ }\text{K}$, agreement recent observation on particles tensile thin films. It was found that decreasing size, i.e., increasing surface volume ratio, unit-cell...

An unusual exchange bias (EB) effect in single-crystalline $\mathrm{GdCr}{\mathrm{O}}_{3}$ compensated ferrimagnet (fM), composed of two antiferromagnetically coupled Gd and Cr sublattices, presenting opposite ferromagnetic (FM) moments, is reported. It shown that the temperature- or field-induced fast reversal net FM moment may be identified as a switching between spin configurations, attendant with abrupt drop Zeeman energy...

Effects of hydrostatic pressure up to $11\phantom{\rule{0.3em}{0ex}}\mathrm{kbar}$ on the magnetic and transport properties ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ (PSMO) were investigated in single crystals with various doping level: $x=0.22,0.24,0.26$, a wide range temperature. In similarity other low doped manganites, PSMO exhibits metal insulator transition magnetoresistance maxima at same temperature $T={T}_{\mathit{MI}}$. It was found that...

Transport and magnetic properties of compacted LaMnO3+δ manganite nanoparticles an average size 18 nm have been investigated in the temperature range 5–300 K. The exhibit a paramagnetic-to-ferromagnetic (FM) transition at Curie TC ∼ 246 However, spontaneous magnetization disappears higher about 270 It was found that low temperatures FM core occupies 50% particle volume. dependence resistivity shows metal–insulator low-temperature upturn below minimum T 50 transport is controlled by charging...

Pressure effect on magnetic properties of polycrystalline La${}_{1\ensuremath{-}x}$Ba${}_{x}$CoO${}_{3}$ (0.1 \ensuremath{\leqslant} $x$ 0.5) was studied by magnetization measurements in the temperature range 5--240 K, field up to 16 kOe, and under hydrostatic pressure 10.5 kbar. For low-doped cobaltites ($x$$=$0.1,0.15), it found that applied enhances ferromagnetic (FM) cluster phase, resulting an increase both spontaneous FM moment transition clusters ${T}_{C}^{\mathrm{cl}}$, while...

We report the structural and magnetic properties of La0.2Ca0.8MnO3 nanoparticles synthesized by a chemical route, having an average diameter 15 nm. Synchrotron experiments performed in temperature range 80−300 K have shown that below 200 transition from room orthorhombic Pnma to monoclinic P21/m space group, associated with orbital ordering, survives studied particles, although this is highly suppressed comparison bulk. The magnetization these particles exhibits appearance ferromagnetic...

Recent experiments showed magnetic moment reversal and pronounced exchange-bias (EB) effect in the vicinity of compensation temperature ${T}_{\mathrm{comp}}$ orthoferrites $R\mathrm{Fe}{\mathrm{O}}_{3}$ ($R=\mathrm{Nd}$, Sm, Er). Although different exhibit diverse $R$-Fe interactions, values, spin-reorientation temperatures, EB field like manner emerges diverges upon approaching changes its sign with crossing ${T}_{\mathrm{comp}}$. In order to explain these observations, a mean-field theory...

Air-stable Fe/Fe3C nanocrystalline particles have been prepared by sonicating Fe(CO)5 in diphenylmethane solutions under argon and subsequently annealing the amorphous as-prepared product an inert atmosphere. Changing sonication conditions temperature allows control of size particles, as well their composition magnetic properties. Material obtained appropriate possesses a high saturation magnetization close to that bulk iron (Ms/M0= 0.97−1.06) good, soft properties (HC = 0.50−0.05 A m-1)....

Transport properties of ${\mathrm{La}}_{0.8}{\mathrm{Ca}}_{0.2}\mathrm{Mn}{\mathrm{O}}_{3}$ thin films 15 and $130\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ thick have been investigated confronted with the bulk single crystals same composition. It has found that low-temperature resistivity is sensitive to electric current and/or field treatment thermal history sample. Thin exhibit a variety metastable resistive states spontaneously evolve toward high-resistivity state in which highly nonlinear...

The effect of hydrostatic pressure P on the magnetic and transport properties self-doped ${\mathrm{La}}_{0.94}{\mathrm{Mn}}_{0.98}{\mathrm{O}}_{3}$ crystals has been investigated at pressures up to 1 GPa in temperature range $15<T<300\mathrm{K}.$ It was found that applied enhances double-exchange coupling, increases magnetization, lowers ferromagnetic-insulator transition temperature. results obtained here for are compared with those observed lightly doped...