Multilayers Prepared .ybco / Lpmo, And Litv Effect

High Temperature Superconductor Cuprate and colossal magnetoresistance material have been called strongly correlated materials. In the two types of material, laser-induced thermoelectric voltage (LITV) effect was found and distributed to anisotropic Seebeck coefficient. Currently, based on this effect, a new rapid response to laser energy / power-meter has been designed and put into application. However, its sensitivity is inferior to semiconductor thermal sensor and bolometer. It demands to design the films that have larger LITV signal, so that the device based on which could be used in detecting weak photon signal. The task of my thesis is to prepare (YBa₂Cu₃O_7-d/La_0.6Pb_0.4MnO₃)_L(L is the period) epitaxial multilayers by pulsed laser deposition technique. X-ray diffraction (XRD), high-resolution electron microscope (HREM), resistance-temperature(R-T) measurements were employed to characterize the property of the multilayer. Additionally, LITV measurements of these multilayers were performed and systemically analyzed. Meantime, possible physical mechanism was discussed.(YBa₂Cu₃O_7-d/La_0.6Pb_0.4MnO₃)_L multilayer were deposited on vicinal-cut LaAlO₃ (100) substrate by pulsed laser deposition technique using the YBa₂Cu₃O_7-d and La_0.6Pb_0.4MnO₃ polycrystalline target, which exhibits an excellent properties. A reliable process is obtained through repeated experiments and summaries. The result of X-ray diffraction showed that the multilayers demonstrates singlecrystalline and epitaxial growth. The result of HREM showed that multilayers demonstrates layered growth and the structure is compact. The result of R-T showed that multilayers demonstrates semiconducting.We found laser-induced thermoelectric voltage effect in the multilayers by the test,the LITV signal has a huge increase ,evev meet to 38V. In comparison with single-layered YBa₂Cu₃O_7-d and La_0.6Pb_0.4MnO₃ thin films, around one order of magnitude enhancement. Secondly, we found that the relationship of peak voltage of multilayers with substrate's tilt angle and thickness accord with single-layered formula, which was educed by Zhang and others. Meanwhile, the respond time of the multilayers LITV signal was influence consumedly by substrate's tilt angle and multilayered period (multilayered thickness). We successfully prepared (YBa₂Cu₃O_7-d/La_0.6Pb_0.4MnO₃)_L multilayers with huge LITV, which provide a new series of materials for laser energy / power-meter with high sensitivity.This kind of multilayers has complex physical property. Some phenomena of the (YBa₂Cu₃O_7-d/La_0.6Pb_0.4MnO₃)_L multilayers are discussed ,such as the effect of substrate's tilt angle, multilayered thickness ,laser energy for the peak of LITV signal. And the effect of substrate's tilt angle, multilayered thickness for respond time of LITV signal .All of the results are very helpful because we can get more information of the materials and explore more applications in future.