Font Size: a A A

Study On The Character Of The Heavy Double-Doped Manganite Film And The Numerical Simulation Of The Film Growth

Posted on:2007-07-02Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y C WangFull Text:PDF
GTID:1101360218957110Subject:Materials Physics and Chemistry
Abstract/Summary:PDF Full Text Request
The measurement of the heavy double-doped La1/3(Ca2/3Sr1/3)2/3MNO3 (LCSMO)thin film, structure and magnetic and optical properties such as a response to theexperimental and numerical simulation studies of the Cu thin film growth, the resultsand conclusions summarized as follows:The properties of the heavy double-doped LCSMO thin film have been systematically studied:①X-ray diffraction pattern indicates that the film is multiphase mixture comprising of perovskitepseudo-cubic phase and orthorhombic phase, since the amount of the orthorhombic phase is veryrare, we can consider that the sample is almost single phase.②the thin film was epitaxial preparedon LaAlO3 (012) single crystal substrate by the pulsed laser deposition method.③The structure ofLCSMO thin film was investigated by X-ray diffractometry, the result indicates that the film isperovskite pseudo-ocubic structure; the preferential orientation is (012).④the surface is relativelysmooth, the growth mode is a typical three-dimensional island growth patterns. The film surfacehas rare crack, which may be the stress produced by unmatched the substrate and the film. Annealafter thin film surface of the island increased, not high; the rift of crystal surface has become lessclear. Thin film structure further improved;⑤The electrical transport property of the film exhibitsa semiconducting behavior, and no metal-insulator transition temperature TMI of the film in thetemperature range of 77K-400K.⑥in weak magnetic field, La1/3(Ca2/3Sr1/3)2/3MNO3 thin film has anegative magnetoresistance effect.⑦when the continual laser irradiated the thin film; wediscovered that the resistance value has increased to the same temperature point. The reason islikely to the photon excitated and thermal effects action together.Under the laser beam irradiation of target heat/mechanics effect, the plasmatransport process as well as the initial period of thin film growth has carried on thenumerical analysis and the simulation study:①Tied the irradiation material dynamicsfrom the pulse the angle to carry on the theoretically discussion to under the pulselaser beam irradiation target heat/mechanics effect, and has carded on the simulationusing the ANSYS software thermal analysis function to the target heat/mechanics effect, has obtained three dimensional temperature field and the thermal stress fielddistribution under the pulse laser irradiation the target. This will have direct or theindirect instructions for the thin film growth by the PLD technology in the future.②According to energy balance consideration, the spatial-characteristic equations ofplasma generated by pulsed laser are obtained by using fluid dynamic theory. Attainedthe plasma production equation, and approximate regards as the plasma in the spatialdissemination the isothermal expansion and the adiabatic expansion two processes,and obtain the plasma spatial transmission equation, carries on the difference to theplasma dissemination equation to solve, many valuable results and the correspondingcurve are obtained;③Summarized the theory of the thin film growth, using dynamicsMonte Carlo (DMC) method, we has studied the thin film growth of initial periodwith the Microsoft.NET technology. The simulation procedures successfully havesimulated Cu thin film growth on the Si substrate by PLD. On the whole, thecalculated results are in agreement with experiments.Using the numerical model may perform parameter optimization. This willprovide the reference for further theoretical and experimental research.
Keywords/Search Tags:perovskite manganite, pulsed laser deposition, CMR thin film, ANSYS software, heat/mechanics effect, plasma transport, dynamics Monte Carlo, the simulation of thin film growth
PDF Full Text Request
Related items