Resonant phonon scattering due to crystal-field-split paramagnetic levels of Pr ions in PrTe1.46

The lattice heat conductivity κ_ph of PrTe_1.46 and LaTe_1.46 has been measured within the 2-to 100-K interval. The quantity ?Δκ_res(T), the decrease in the heat conductivity caused by resonant phonon scattering due to crystal-field-split paramagnetic levels of Pr, was derived from experimental data using the relation $ - \Delta \kappa _{res} (T) = \kappa _{ph(PrTe_{1.46} )} (T) - \kappa _{ph(LaTe_{1.46} )} (T)$ . The energy of the first split paramagnetic level of Pr, Δ₁ was calculated from the Δκ_res(T) relation for T<T _res. It was found that Δ₁ depends on the nature of the nearest neighbor environment of Pr ions in the lattice. The temperature dependence Δκ_res(T) has been determined to be Δκ_res(T) (Δκ_res～T ^?0.5) for T>T _res.     

Heat capacity of BiFeO3-based multiferroics

The heat capacity of Bi_{1 ? x} Re _x FeO₃ (Re = La, Eu, Ho; x = 0, x = 0.05) multiferroics has been studied in the temperature range of 120–800 K. The substitution of a small amount of rare-earth elements for bismuth leads to a significant increase in the heat capacity in the broad temperature range studied. It is established that the temperature dependence of the excess heat capacity is related to the Schottky effect for three-level states certain that appear as a result of structure distortions in the rare-earth-doped compositions.     

The Schottky Effect in Bi0.95Sm0.05FeO3

Physics of the Solid State - The temperature dependence of the specific heat of the Bi0.95Sm0.05FeO3 multiferroic has been studied in the temperature range 130–780 K. The substitution of...     

Influence of the Multiplet Levels of Sm3+ and Eu3+ on the Heat Capacity of Multiferroic BiFeO3

Physics of the Solid State - The temperature dependence of the heat capacity of multiferroics BiFeO3, Bi0.90Sm0.10FeO3, and Bi0.90Eu0.10FeO3 has been investigated. It is found that the substitution...     

Heat capacity of the 0.7PbNi1/3Nb2/3O3-0.3PbTiO3 ferroelectric ceramics

The temperature dependence of the heat capacity of the 0.7PbNi_1/3Nb_2/3O₃-0.3PbTiO₃ compound has been studied in the temperature range 120?C800 K. The temperature dependence of the heat capacity C _p has two diffuse anomalies in the temperature ranges 250?C450 K and 450?C650 K and a ?? anomaly at temperatures T ?? 225 K. The results are discussed with inclusion of the dielectric and structural data.     

Phonon Scattering by Paramagnetic Ions of Europium and Samarium in Bismuth Ferrite

Physics of the Solid State - Temperature dependences of the thermal diffusivity and thermal conductivity in multiferroic materials BiFeO3, Bi0.90Sm0.10FeO3, and Bi0.90Eu0.10FeO3 were studied....     

Thermal physical properties of ferroelectric ceramics PKR-7M near the diffuse phase transition

The thermal physical properties (heat capacity, thermal expansion coefficient, and deformation) of a relaxor piezoelectric ceramics based on the lead zirconate titanate PKR-7M have been studied in the temperature range 200–800 K. Diffuse anomalies have been revealed in the temperature dependences of the heat capacity and thermal expansion over wide temperature ranges 270–650 and 450–600 K, respectively. It has been shown that the anomalous behavior of the heat capacity is due to the manifestation of two-level states (Schottky anomalies). The results of the study have been discussed together with the data of structural studies.     

Specific Heat and the Dielectric Properties of Bi0.8Ho0.2FeO3 Multiferroic

Physics of the Solid State - The specific heat and the dielectric permittivity of Bi0.8Ho0.2FeO3 multiferroics have been studied in the wide temperature range 300–750 K. The doping with...     

Heat capacity of multiferroics Bi1–x Pr x FeO3

Physics of the Solid State - The heat capacity of multiferroics Bi1–x Pr x FeO3 (0 ≤ x ≤ 0.20) has been studied in the temperature range 130–800 K. An insignificant...     

Thermophysical properties of PLZT ferroelectric ceramics with a nanopolar structure

The heat capacity, thermal expansion coefficient, and deformation of the PLZT-9/65/35 compound are studied in the temperature range 150–800 K. Diffuse anomalies are detected in the temperature dependences of the heat capacity and thermal expansion coefficient over wide temperature ranges of 250–650 and 330–550 K, respectively. The anomalous behavior of the heat capacity in the temperature range 250–650 K is shown to be caused by the appearance of two-level states (Schottky anomaly). The results obtained are discussed along with the data of structural and dielectric studies.