Elastocaloric Effect in PbTiO$_{3}$ Thin Films with 180$^{\circ}$ Domain Structure: A Phase Field Study
Fang Wang1,3, Bo Li2**, Yun Ou1,3, Long-Fei Liu1,3**, Wei Wang4
1Hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment, Hunan University of Science and Technology, Xiangtan 411201 2School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105 3School of Materials and Engineering, Hunan University of Science and Technology, Xiangtan 411201 4China Three Gorges Corporation, Chengdu 610041
Abstract：The elastocaloric effect of PbTiO$_{3}$ thin films with 180$^{\circ}$ domain structure is studied using the phase field method. The influence of external stress $\sigma_{33}$, misfit strain $u_{\rm m}$ and domain wall energy on the adiabatic temperature change ($\Delta T_{\sigma})$ at room temperature are carried out. The calculation results indicate that $|{\Delta T_\sigma}|$ increases as $|{\sigma_{33}}|$ or $|{u_{\rm m}}|$ increases. The largest $\Delta T_{\sigma}$ value of $-$7.8 K is obtained at $\sigma_{33}=2$ GPa and $u_{\rm m}=-0.02$. Furthermore, the domain switching behaviors under different gradient coefficients are different, and finally affect the elastocaloric effect in PTO thin films. These results could provide a guide to choose the substrate and the preparation process in experiments.
2018, Vol. 35 
