Enhanced piezoelectric and mechanical properties of AlN-modified BaTiO3 composite ceramics.
BaTiO3-xAlN (BT-xAlN) composite ceramics were prepared by conventional solid state reaction sintering. The effects of the AlN content on the crystalline structures, densities, and electrical and mechanical properties of the BT ceramics were investigated. The BT-1.5%AlN ceramic exhibits a good piezoelectric constant of 305 pC N(-1) and an improved Vickers hardness of 5.9 GPa. The enhanced piezoelectricity originates from interactions between defect dipoles and spontaneous polarization inside the domains due to the occurrence of local symmetry, caused by the preferential distribution of the Al(3+)-N(3-) pairs vertical to the c axis. The hardening of the material is attributed to the improved density, and particle and grain boundary strengthening. Our work indicates that if a suitable doping ion pair is designed, lead-free ceramic systems prepared from ordinary raw materials by a conventional sintering method have a high probability of exhibiting good piezoelectric and mechanical properties simultaneously.
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China. wdfei@hit.edu.cn.
Dan
D
Xu
Lidong
L
Wang
Weili
W
Li
Wei
W
Wang
Yafei
Y
Hou
Wenping
W
Cao
Yu
Y
Feng
Weidong
W
Fei
D017607:Aluminum Compounds / Q000737:chemistry*; D017609:Barium Compounds / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D019245:Compressive Strength; D003460:Crystallization; D004553:Electric Conductivity; D004574:Electromagnetic Fields; D006244:Hardness; D008422:Materials Testing; D055617:Micro-Electrical-Mechanical Systems / Q000379:methods*; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry*
D017607:Aluminum Compounds; D017609:Barium Compounds; C024547:barium titanate(IV); C052045:aluminum nitride; D014025:Titanium