Related papers: The Phase Separation Scenario for Manganese Oxides
A first order phase transition between a BCS phase and an insulating Mott phase for a gas of spatially separated electrons and holes with tunable Coulomb interaction and variable density is predicted. In the framework of a BCS-like…
The effect of $^{16}$O $\to$ $^{18}$O isotope substitution on electrical resistivity and magnetic susceptibility of Sm$_{1-x}$Sr$_x$MnO$_3$ manganites is analyzed. It is shown that the oxygen isotope substitution drastically affects the…
In the present work, low compensated insulating (Ga,Mn)As with 0.7% Mn is obtained by ion implantation combined with pulsed laser melting. The sample shows variable-range hopping transport behavior with a Coulomb gap in the vicinity of the…
Using numerical techniques and asymptotic expansions we obtain the phase diagram of a paradigmatic model of Coulomb frustrated phase separation in systems with negative short-range compressibility. The transition from the homogeneous phase…
Effects of disorder on the two competing phases, i.e., the ferromagnetic metal and the commensurate charge/lattice ordered insulator, are studied by Monte Carlo simulation. The disorder suppresses the charge/lattice ordering more strongly…
Mixed valent manganites are noted for their unusual magnetic,electronic and structural phase transitions. The La1-xCaxMnO3 phase diagram shows that below transition temperatures in the range 100-260 K, compounds with 0.2 < x < 0.5 are…
A microscopic characterisation of the phase transitions associated with colossal magnetoresistance (CMR) in manganese perovskite oxides is a very important ingredient in the quest of understanding its underlying mechanism. Scanning…
We consider the ground state magnetic phase diagram of the two-dimensional Hubbard model with nearest and next-nearest neighbor hopping in terms of electronic density and interaction. We treat commensurate ferro- and antiferromagnetic, as…
The nature of phase separation in $Pr_{0.5}Sr_{0.5}MnO_3$ has been probed by linear as well as nonlinear magnetic susceptibilities and resistivity measurements across the 2nd order paramagnetic to ferromagnetic transition ($T_C$) and 1st…
The phase diagram and low temperature properties of the doped manganites A1-xBxMnO3 are discussed for the concentrations x < 0.4. The transition from insulating antiferromagnetic to metallic ferromagnetic state at x_cr = 0.16 is treated by…
The Monte Carlo Ferromagnetic Ising model was used to study the electrical properties of manganese oxides due to the charge ordering phase occurring at doping, x = 0.5. The half-doped manganites have an insulator antiferromagnetic ground…
Characteristic signatures of statistical Coulomb fragmentation of highly excited nuclear systems were analyzed. It was found that in some important aspects, they coincide with perceived signatures of phase transitions in confined…
Within the framework of the $s$-$d(f)$ exchange model in the mean-field approximation for square, simple cubic, body-centered and face-centered cubic lattices, the formation of a ferromagnetic, spiral, and commensurate antiferromagnetic…
We have considered the model of the phase transition of the second order for the Coulomb frustrated 2D charged system. The coupling of the order parameter with the charge was considered as the local temperature. We have found that in such…
The zero-field $^{139}$La and $^{55}$Mn nuclear magnetic resonances were studied in $\rm La_{0.8}Ca_{0.2}MnO_{3+\delta}$ with different oxygen stoichiometry $\delta$. The signal intensity, peak frequency and line broadening of the…
Ultrafast optical excitations allow creating new metastable and hidden states in quantum materials. However, the fundamental material properties required to support new emergent order are largely unknown. Here we show for two colossal…
Detailed magnetization measurements in La_{5/8-y}Pr_{y}Ca_{3/8} MnO_{3}, including magnetic relaxation properties, demonstrate the dynamic nature of the phase separated state in manganites. The difference between the field-cooled-cooling…
We study the competition between long-range and short-range interactions among holes within the spin density wave picture of layered transition metal oxides. We focus on the problem of charge ordering and the charge phase diagram. We show…
Antiferromagnetic-insulating(AF-I) and the ferromagnetic-metallic(FM-M) phases coexist in various half-doped manganites over a range of temperature and magnetic field, and this is often believed to be an essential ingredient to their…
General properties of anisotropic superconductors with mesoscopic phase separation are analysed. The main conclusions are as follows: Mesoscopic phase separation can be thermodynamically stable only in the presence of repulsive Coulomb…