Wang Genshui

Mechanism of the Pyroelectric Response under Direct-Current Bias in La-Modified Lead Zirconate Titanate Stannate Ceramics

Dielectric and pyroelectric properties of Pb0.97La0.02(Zr0.42Sn0.40Ti0.18)O3 ceramics are investigated as functions of temperature and dc bias field. Induced and intrinsic pyroelectric coefficients pind and p0 are calculated and analyzed. It is found that the sign, value and variation of the net pyroelectric coefficient p with increasing dc bias all are dominated by p0 under applied biases. Polarization and depolarization processes under dc biases are analyzed. Besides the contribution of pind, the diffuse and decreased pyroelectric response under dc bias compared with that of an identical field poled sample without dc bias is mainly attributed to the depolarization process under dc bias.

Growth, Magnetic and Electrical Transport Properties of La

La0.7Sr0.3MnO3 (LSMO) thin films with different thicknesses were deposited on (Pb0.97La0.02) (Zr0.58Sn0.3025Ti0.1175)O-3 (PLZST) ceramics by RF magnetron sputtering, and their microstructure, magnetic and electrical transport properties were investigated. Microscopy observations show that LSMO thin films are perovskite structure without obvious impurity phase. All the LSMO thin films display smooth surface with uniform, and roughness is as low as 2.93 nm for LSMO thin films at the thickness of 20 nm. Furthermore, large magnetoresistance (MR) effect was observed in LSMO thin films in a broad temperature range of 10-300 K. Particularly the MR of LSMO thin films with 20 nm in thickness exhibits excellent temperature stability. Moreover, the Curie temperature, metal-insulator transition temperature, saturation magnetization and electrical conductivity decrease as the film thickness increases, which is attributed to the diffusion of Pb, Sn, Zr, etc. in the samples, resulting in the distortion of MnO6 octahedron.采用磁控溅射法在PLZST陶瓷衬底上制备了不同厚度的LSMO薄膜, 并对其微结构、磁性能及电输运特性进行了研究。结果表明, LSMO薄膜具有单一钙钛矿结构, 晶粒均匀, 表面平整, 其中20 nm厚LSMO薄膜粗糙度仅为2.93 nm。在10~300 K温度范围内, LSMO薄膜均具有大的磁电阻效应, 20 nm厚的LSMO薄膜磁电阻温度稳定性优异。随着薄膜厚度的增加, 薄膜的居里温度、金属绝缘体转变温度、磁化强度和导电性能降低。这可能是由于Pb、Sn、Zr等离子扩散进入LSMO薄膜中, 导致MnO 6 八面体畸变造成的。采用磁控溅射法在PLZST陶瓷衬底上制备了不同厚度的LSMO薄膜, 并对其微结构、磁性能及电输运特性进行了研究。结果表明, LSMO薄膜具有单一钙钛矿结构, 晶粒均匀, 表面平整, 其中20 nm厚LSMO薄膜粗糙度仅为2.93 nm。在10~300 K温度范围内, LSMO薄膜均具有大的磁电阻效应, 20 nm厚的LSMO薄膜磁电阻温度稳定性优异。随着薄膜厚度的增加, 薄膜的居里温度、金属绝缘体转变温度、磁化强度和导电性能降低。这可能是由于Pb、Sn、Zr等离子扩散进入LSMO薄膜中, 导致MnO 6 八面体畸变造成的。

lt;inf

The phase transitions, dielectric properties, and polarization versus electric field (P-E) hysteresis loops of Pb0.97La0.02(Zr0.42Sn0.58-xTix)O-3 (0.13 < x < 0.18) (PLZST) bulk ceramics were systematically investigated. This study exhibited a sequence of phase transitions by analyzing the change of the P-E hysteresis loops with increasing temperature. The antiferroelectric (AFE) to ferroelectric (FE) phase boundary of PLZST with the Zr content of 0.42 was found to locate at the Ti content between 0.14 and 0.15. This work is aimed to improve the ternary phase diagram of lanthanum-doped PZST with the Zr content of 0.42 and will be a good reference for seeking high energy storage density in the PLZST system with low-Zr content.