Specific heat and heat conductivity of the BaTiO3 polycrystalline films with the thickness in the range 20 - 1100 nm

Thermal properties - specific heat and heat conductivity coefficient - of polycrystalline BaTiO3 films on massive substrates were studied as a function of the temperature and the film thickness by ac-hot probe method. The anomalies of specific heat with decreasing of the film thickness from 1100 to 20 nm revealed the reducing of critical temperature (Tc) and excess entropy of the ferroelectric phase transition, which becomes diffused. The critical thickness of the film at which Tc = 0 estimated as 2.5 nm.Comment: 12 pages, 7 figures, 2 tables, 450kb; submitted to J.Phys.:Cond.Mat

Russian population health-related quality of life indicators calculated using the EQ-5D-3L questionnaire

Objectives. The paper aims was forming the first health-related quality of life population indicators using EQ-5D–3L survey that represents the Russian population by gender and age, as well as by the attained level of education. Material and methods. For compiling population indicators, we use the EQ-5D-3L questionnaire. The study was conducted on the adult Russian population aged 18 to 75 years. A representative sample was 12616 respondents. Results. 59.3 % of the sample is in good health (profile 11111). The proportion of respondents reporting any health problems increases with age. The average score on a 100-point visual analogue scale is 72.4 (standard deviation 18,1; 95 per cent confidence interval from 72,1 to 72,7). Men, on average, tend to assess their health higher than women. However there are no statistically significant differences in health scores among educational groups, taking into account gender and age data. Conclusions. Comparison of health-related quality of life estimations with normative population data allows us to track differences in health between population groups, as well as to analyze the health status and progress in treating patients. The Russian health-related quality indicators from EQ-5D-3L survey are similar to the Hungary population indices, as well as to many European countries, the USA, and Argentina for age cohorts under 45 years of age. For the cohorts of respondents older than 45 years, Russian estimations are much lower than in other countries. This evidence confirms that borrowing scales from other countries for converting EQ-5D-3L values into a preference EQ-5D-3L index is not acceptable for Russian patients, especially for the elderly

Evidence of Substrate-Induced Ferroelectric Phase Transition in SrTiO3 by Means of Thermal Measurements

The paper reports the results of the temperature dependence measurements of the specific heat for a SrTiO3 thin (104 nm) film deposited on a DyScO3 substrate. Two anomalies of the specific heat have been observed. They can be associated with the strain-induced ferroelectric phase transition (at 304K) and the shifted antiferrodistortive structural phase transition (at 173 K).

Features of Phase Transitions in Nanostructured Ferroelectric Oxides Revealed from Calorimetric Data

A short review of the study of thermal properties of the nanostructured ferroelectrics is given. An application of the modern calorimetric technique to a comparative study of phase transitions in the ferroelectric nanostructured materials (polycrystalline and epitaxial thin films, superstructures, ferroelectric heterostructures, substrate-induced ferroelectricity) is considered.