Resistance Measurement of Nano-order Thickness Surface Layer of YBa2Cu3O7-y Crystal

用声表面波技术测量了YBa2Cu3O7-y晶体样品的表面电阻。表面声波与晶体中载流子的耦合是通过沿样品表面传播的静电势脉冲实现的。由于静电感应效应，从样品中筛选出了电势脉冲。在室温下，电势脉冲在样品表面的穿透深度小于1 nm。表面电阻对升温和降温测量的温度依赖性不同。此外，表面电阻取决于表面层中的缺氧量。

A surface acoustic wave technique was used to measure the surface resistance of YBa2Cu3O7-ycrystal sample. The coupling of the surface acoustic wave to carriers in the crystal was through an electrostatic potential pulse propagating along the surface of the sample. The potential pulse was screened out from the sample due to an electrostatic induction effect. Penetration depth of the potential pulse into the sample was below 1 nm from the surface at room temperature. There were different temperature dependences of the surface resistance on warming and cooling measurements. Also, the surface resistance depends on oxygen deficiency in the surface layer.