脉冲激光沉积生长单相的Nd_(1.85)Ce_(0.15)CuO_4薄膜及其激光感生热电电压效应  

Preparation of single-phase Nd_(1.85)Ce_(0.15)CuO_4 thin films by pulse laser deposition and the laser-induced thermoelectric voltage effect

作　　者：熊飞[1,2] 张辉[1] 张鹏翔[1] 蒋最敏[2] 

机构地区：[1]昆明理工大学光电子新材料研究所,昆明650051 [2]复旦大学应用表面物理国家重点实验室,上海200433

出　　处：《功能材料与器件学报》2009年第2期113-119,共7页Journal of Functional Materials and Devices

基　　金：国家自然科学基金(批准号:10274026)

摘　　要：采用脉冲激光沉积(PLD)技术,在SrTiO3单晶衬底表面外延生长单相的Nd1.85Ce0.15CuO4(NCCO)薄膜,并首次在斜切衬底上生长的NCCO薄膜中探测到激光感生热电电压(LITV)信号。实验研究表明,在低沉积温度、高沉积氧压和较大的激光脉冲重复频率下生长的NCCO薄膜中存在Nd1-xCexO1.75(NCO)杂相,是由于衬底表面吸附粒子扩散迁移困难所致;而高温下真空退火导致杂相的产生,则与NCCO的结构相变引起的热分解有关。通过提高沉积温度、降低沉积氧压和激光脉冲重复频率、并采用低温(T≤800℃)真空退火的方式,可以抑制杂相的形成。制备得到的单相的NCCO外延薄膜是一种新型的原子层热电堆材料,能量为1mJ的紫外脉冲激光的辐照,可以在倾斜的NCCO薄膜中诱导产生0.8V的LITV信号。The single-phase Nd1. 85 Ce0.15 CHO4 （NCCO） thin films were deposited epitaxially on SrTiO3 sub- strate by pulse laser deposition （PLD）. And for the first time, the laser-induced thermoelectric voltage （LITV） signals were detected in the NCCO thin films grown on the vicinal cut substrate. The Nd1-x,CexO1.75 （NCO） impurities were always observed in the NCCO films prepared under the condition of low deposition temperature as well as high oxygen pressure and laser pulse frequency. The difficult mobility of the absorbed particles on the substrate surface contributed to the existence of NCO, and the annealing process at high temperature was also play an important role which was associated with the thermal decomposition due to the structural phase-transition. The impurities can be suppressed by increasing the deposition temperature but decreasing the laser pulse frequency and oxygen pressure, and vacuum annealing at temperature below 800℃. The epitaxial NCCO thin films with a single phase were demonstrated to be a new type of atomic thermopile material. LITV signals of 0.8V were detected when the tilted NCCO thin films were illuminated by pulse-laser of 248nm and the on -sample energy was just 1mJ.

关 键 词：Nd1.85Ce0.15CuO4薄膜 激光感生热电电压效应 脉冲激光沉积 X射线衍射 

分 类 号：TM262[一般工业技术—材料科学与工程] O484.1[电气工程—电工理论与新技术]