Тип публикации: статья из журнала
Год издания: 2017
Идентификатор DOI: 10.1142/S2010135X17500412
Ключевые слова: Electrocaloric effect, ferroelectrics, layered structures, nonequilibrium conditions, phase transitions
Аннотация: We present the results of studies of thermal expansion, heat capacity, permittivity, polarization and the influence of different thermal conditions on the intensive electrocaloric effect (ECE), Delta T-AD, in a commercial multilayer capacitor based on doped BaTiO3. Investigations in a wide temperature range revealed one anomaly in Показать полностьюthe behavior of the physical properties at about 290K characteristic for the relaxors. Direct measurements showed a high reversibility of ECE under equilibrium thermal conditions. Good agreement was found between the values of Delta T-AD determined by direct and indirect measurements at the electric field up to 15.4 kV/cm. Quasi-isothermal conditions lead, firstly, to decrease of large Delta T-AD approximate to 0.94K obtained in adiabatic conditions under E = 308 kV/cm to 0.87 K, and, secondly, the appearance of a difference between the values of Delta T-ON and Delta T-OFF determined when the electric field is applied and removed. Using this phenomenon and changing the frequency of the periodic electric field, E = 15: 4 kV/cm, the effect of cooling was obtained equal to (Delta T-ON + Delta T-OFF)/2](max) = -0.032 K. The results obtained are useful for further development of the electrocaloric refrigeration technique without thermal switches.
Журнал: JOURNAL OF ADVANCED DIELECTRICS
Выпуск журнала: Vol. 7, Is. 6
Номера страниц: 1750041
ISSN журнала: 2010135X
Место издания: SINGAPORE
Издатель: WORLD SCIENTIFIC PUBL CO PTE LTD