MgO(100)衬底上生长BaTi_2O_5薄膜及其性能研究

Study on Growth and Properties of BaTi_2O_5 Thin Films Deposited on MgO(100) Substrates

利用脉冲激光沉积技术，在MgO（100）衬底上生长了BaTi2O5薄膜，探讨了沉积条件（衬底温度和氧分压）对薄膜结构的影响，并对其介电和光学性能进行了研究。结果表明：随衬底温度和氧分压的改变，BaTi2O5薄膜的物相和结晶取向逐渐变化；适宜的脉冲激光沉积工艺为衬底温度950～1000K、氧分压12．5Pa，在该条件下获得了b轴方向择优生长的BaTi2O5薄膜；该薄膜具有较高的居里温度（750K），介电常数达2000，而且在可见光和红外波长范围内具有较高的透过率。

BaTi2O5 thin films were prepared on MgO （100） substrates by pulsed laser deposition. The effect of deposition conditions on structure and properties of the films were investigated. The results indicate the crystal structure and preferred orientation of the films changed with substrate temperatures （Tsub ） and oxygen partial pressures （Po2）. BaTi2O5 film with significant b-axis preferred orientation was obtained at Tsub = 950-1000 K and Po2 = 12.5 Pa. The b-axis oriented BaTi2O5 film exhibited a sharp dieletrie constant maximum of 2000 and a high Curie temperature （750 K ）. The film was highly transparent in the visible and infrared region with a transmittance above 70%.