Related papers: Transverse ultrasonic anomaly in La1/3Sr2/3MnO3
Magnetic spinels (with chemical formula $AX_{2}$O$_{4}$, with $X$ a 3$d$ transition metal ion) that also have an orbital degeneracy are Jahn-Teller active and hence possess a coupling between spin and lattice degrees of freedom. At high…
We report on the temperature dependent Raman spectroscopic studies of orthorombic distorted perovskite YCrO3 in the temperature range of 20-300K. Temperature dependence of DC-magnetization measurement under field cooled and zero field…
We report Electron Paramagnetic Resonance measurements on single crystalline and powder samples of Nd_0.5Ca_0.5MnO_3 across the charge-ordering transition at T_co=240 K down to the antiferromagnetic ordering transition at T_N = 140 K. The…
We have investigated the dielectric anomalies associated with spin ordering transitions in the tetragonal spinel Mn$_3$O$_4$, using thermodynamic, magnetic, and dielectric measurements. We find that two of the three magnetic ordering…
Measurements of magnetic susceptibility, heat capacity and thermal expansion are reported for single crystalline CuSb$_{2}$O$_{6}$ in the temperature range $5<T<350$ K. The magnetic susceptibility exhibits a broad peak centered near 60 K…
The longitudinal ultrasonic sound velocity and attenuation, the resistivity, and lattice parameters were studied as a function of temperature from 30 K to 300 K in La1-xCaxMnO3 (0.5<x<0.9). For all the samples, a dramatic stiffening of the…
Materials which possess coupling between different degrees of freedom such as charge, spin, orbital and lattice are of tremendous interest due to their potential for device applications. It has been recently realized that some of manganite…
We have measured near normal incidence far infrared (FIR) reflectivity spectra of a single crystal of TbMnO3 from 10K to 300K in the spectral range of 50 cm$^{-1}$ to 700 cm$^{-1}$. Fifteen transverse optic (TO) and longitudinal optic (LO)…
Two magnetic ordering transitions are found in InMnO3, the paramagnetic to antiferromagnetic transition near ~118 K and a lower possible spin rotation transition near ~42 K. Multiple length scale structural measurements reveal enhanced…
The ultrasonic properties of La$_{1-x}$Ca$_{x}$MnO$_{3}$ ($x\approx 0.25$) with the Curie temperature $T_C$ about 200 K are studied. Temperature dependences of longitudinal and transverse sound velocities were measured in zero magnetic…
One- and multi-phonon excitations of the single crystalline LaCoO3 were studied using Raman spectroscopy in the temperature region of 5 K - 300 K. First-order Raman spectra show a larger number of phonon modes than allowed for the…
We report a novel dielectric anomaly around the Jahn-Teller orbital order-disorder transition temperature T_JT in LaMnO_(3+delta). The transition has been characterized by resistivity (rho)versus temperature (T), calorimetry, and…
The analysis of phonon anomalies provides valuable information about the cooperative dynamics of lattice, spin and charge degrees of freedom. Significant is the anomalous temperature dependence of the external modes observed in…
We report an infrared reflection spectroscopy study of La$_{1/2}$Ca$_{1/2}$MnO$_3$ over a broad frequency range and temperature interval which covers the transitions from the high temperature paramagnetic to ferromagnetic and, upon further…
Infrared reflectivity spectra of cubic SrMnO$_{3}$ ceramics reveal 18 % stiffening of the lowest-frequency phonon below the antiferromagnetic phase transition occurring at T$_{N}$ = 233 K. Such a large temperature change of the polar phonon…
The transport and magnetic properties of correlated La{0.53}Sr{0.47}MnO{3} ultrathin films, grown epitaxially on SrTiO{3}, show a sharp cusp at the structural transition temperature of the substrate. Using a combination of experiment and…
Spin-phonon coupling effects, as reflected in phonon frequency shifts between ferromagnetic (FM) and G-type antiferromagnetic (AFM) configurations in cubic CaMnO$_3$, SrMnO$_3$, BaMnO$_3$, LaCrO$_3$, LaFeO$_3$ and La$_2$(CrFe)O$_6$, are…
We determine the nature of coupled phonons and magnetic excitations in AlFeO3 using inelastic light scattering from 5 K to 315 K covering a spectral range from 100-2200 cm-1 and complementary first-principles density functional theory-based…
The low-doped magnetic perovskite La_{7/8}Sr_{1/8}MnO_3 undergoes within the paramagnetic-semiconducting phase a first-order structural transition due to antiferrodistorsive ordering of Jahn-Teller deformed MnO_6 octahedra. This allows to…
We investigate three dimensional anharmonic phonons in tetrahedral symmetry and superconductivity mediated by these phonons. Three dimensional anharmonic phonon spectra are calculated directly by solving Schr\"odinger equation and the…