Cmr Films Preparation And Litv Of The Device Design

The Laser Induced Thermoelectric Voltage(LITV) of LaCaMnO3thin films which is a typical CMR materials and YBa2Cu3O7-. thin films which is a typical High Temperature Superconductor deposited on vicinal cut substrate has become a new direction for study internationally. The main topic of this thesis is to deposit LaCaMnO3 thin films by pulsed laser deposition(PLD) technology, and to make thin film device by using optic-erosion technology . We can fabricate a laser energy/power meter of LaCaMnO3 thin fihns based on anisotropic Seebeck effect in crystal and on the linear relationship between peck of LITV and laser energy/power. We also can fabricate a new model-detector of laser based on array of thin film receiving different energy/power.La1-xCaxMnO3 thin fihns in which the doping lever of Ca were 0.05,0.1,0.15,and 033 respectively were prepared on SrTiO3 and LaAlO3 substrates by pulsed laser deposition method using the high quality La1-xCaxMnO3 polycrystalline targets. We have obtained a lot of experience after many experiments. The result of AFM photograph shows that the surfaces of these fihns are flat and smooth, and the result of LITV measuring experiments show that the La0.9Ca0.1MnO3 thin fihns deposited on vicinal cut LaAlO3 substrate with tilted angle of 20 have the largest peck voltage of LITV signal.Based on the equation of LITV which was deduced by H. Lengfellner and his partners and on the formula of the time dependence of laser induced voltage from HTSC and CMR thin fihns by P. X. Zhang using the plane heat source and micro-cell model, we have deduced the function by which one can obtain the optimum thickness for producing largest laser induced thermoelectric voltage.After calculation, we get the optimum thickness of La0.9Ca0.1MnO3 thin film deposited on vicinal cut LaAlO3 substrate(10) is 190.0nm, and the optimum thickness of YBa2Cu3O7- thin film deposited on vicinal cut SrTiO3 substrate(10) is 243nm.We also have fabricated a monitor device of laser energy/power meter by using a singlechip for showing the measure results of LITV signal generated by pulsed laser. The display set of the device is made of three LEDs from which we can read the measuring result for laser energy/power. The result of testing the performance of the device shows that the device can work well under some situation, which will benefit the later work for fabricating new device. But it also has it defects and need to be improved in designment. We come up with some idea for improving in the thesis.