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A study was conducted to examine the heat capacity of charge-ordered [La.sub.0.5][Ca.sub.0.5]Mn[O.sub.3] using double-exchange-Holstein model. Findings highlight the dominance of the lattice contribution, especially in ferromagnetic regime.

Phonon properties have been studied using reduced sound velocity of Eu0.5Ba0.5TiO3 (EBTO). To achieve this aim, the anharmonic phonon-phonon interaction and the spin-phonon interaction were used. It was shown that the reduced sound velocity of multiferroic EBTO exhibits a kink at TN = 1.9 K. This anomalously reduced sound velocity can be interpreted as an effect of vanishing magnetic ordering above TN. What’s more, the ferroelectric subsystem cannot be influenced by the magnetic subsystem above TN for TN ≪TC in the EBTO. It was found that the reduced sound velocity decreases as T increases near ferroelectric transition TC. That is to say, the sound velocity softens near ferroelectric transition TC. It is also noteworthy that the reduced sound velocity softens when the RE (the coupling between the ferroelectric pseudo-spins and phonons), V(3) and |V(4)| (the third- and fourth-order atomic force constants of the anharmonic phonons, respectively) increase. These conclusions are all in good accordance with the experimental data and theoretical results. [ABSTRACT FROM AUTHOR]

Phonon properties have been studied using reduced sound velocity of Eu0.5Ba0.5TiO3 (EBTO). To achieve this aim, the anharmonic phonon-phonon interaction and the spin-phonon interaction were used. It was shown that the reduced sound velocity of multiferroic EBTO exhibits a kink at TN = 1.9 K. This anomalously reduced sound velocity can be interpreted as an effect of vanishing magnetic ordering above TN. What’s more, the ferroelectric subsystem cannot be influenced by the magnetic subsystem above TN for TN ≪TC in the EBTO. It was found that the reduced sound velocity decreases as T increases near ferroelectric transition TC. That is to say, the sound velocity softens near ferroelectric transition TC. It is also noteworthy that the reduced sound velocity softens when the RE (the coupling between the ferroelectric pseudo-spins and phonons), V(3) and |V(4)| (the third- and fourth-order atomic force constants of the anharmonic phonons, respectively) increase. These conclusions are all in good accordance with the experimental data and theoretical results. [ABSTRACT FROM AUTHOR]

This note describes how to theoretically calculate and experimentally measure the moment of inertia of a Ping-Pong[R] ball. The theoretical calculation results are in good agreement with the experimental measurements that can be reproduced in an introductory physics laboratory.

Highlights: [•] ɛ′(T) of La0.5Ca0.5MnO3 are investigated by EOM GF. [•] The intensity of ɛ′(T) reduced with the increase of |ɛJT |, V, U. [•] TP rises as |ɛJT |, V, and U increase. [•] TP remains unchanged and ɛ′(T) increased with the increase of g. [•] The calculated results of ɛ′(T) are explained theoretically. [Copyright &y& Elsevier]

Abstract: In this paper, the microscopic theory of the relative change in velocity of sound with temperature of La0.5Ca0.5MnO3 is reported. The phonon Green function is calculated using the Green function technique of Zubarev in the limit of zero wave vector and low temperature. The lattice model electronic Hamiltonian in the presence of the phonon interaction with hybridization between the conduction electrons and the l-electrons is used. The relative change in velocity of sound at various temperatures is studied for different model parameters, namely the position of the l-level, the effective phonon coupling strength and hybridization strength. The phonon anomalies observed experimentally at different temperatures are explained theoretically. An abrupt change in velocity at Neel temperature (TN ) is observed clearly. It is observed that different parameters influence the velocity of sound. [Copyright &y& Elsevier]

Abstract: In this Letter the microscopic theory of the relative change in velocity of sound with temperature of La0.5Ca0.5MnO3 is reported. The phonon Green function is calculated using the Green function technique of Zubarev in the limit of zero wave vector and low temperature. The lattice model electronic Hamiltonian in the presence of the phonon interaction with hybridization between the conduction electrons and the l-electrons is used. The relative change in velocity of sound at various temperatures is studied for different model parameters namely the position of the l-level, the effective phonon coupling strength and hybridization strength. The phonon anomalies observed experimentally at different temperatures are explained theoretically. An abrupt change in velocity at Neel temperature () is observed clearly. It is observed that different parameters influence the velocity of sound. [Copyright &y& Elsevier]

Abstract: In this letter, an oxide heterostructure has been fabricated by successively growing La0.7Sr0.3MnO3 (LSMO) and BiFeO3 (BFO) layers on LaAlO3 (100) by pulsed laser deposition. Analysis of the leakage current at different temperature demonstrated that the Poole–Frenkel dominated the leakage current mechanism. Additionally, the BiFeO3/La0.7Sr0.3MnO3 heterostructure exhibits a positive colossal magnetoresistance (MR) effect over a temperature range of 50–320K. The maximum MR values are determined to be about 45.32% at H =0.5T and 28.34% at H =0.3T. At last, we report photoconductivity in BiFeO3/La0.7Sr0.3MnO3 film under illumination from 160mW/cm2 and 200mW/cm2 green-light source, and photoconductivities increase with the intensity of light enhanced. [Copyright &y& Elsevier]