D.M. Dolginzev - Research Engineer, Russian State Pedagogical University. A. I. Herzen (St. Petersburg). Е-mail: thphys@herzen.spb.ru A.G. Kanareikin - Post-Graduate Student, Russian State Pedagogical University. A. I. Herzen (St. Petersburg). Е-mail: thphys@herzen.spb.ru V.P. Pronin - Dr.Sc. (Phys.-Math.), Professor, Russian State Pedagogical University. A. I. Herzen (St. Petersburg). Е-mail: thphys@herzen.spb.ru E.Yu. Kaptelov - Dr.Sc. (Phys.-Math.), Senior Research Scientist, Russian State Pedagogical University. A. I. Herzen (St. Petersburg). Е-mail: Kaptelov@mail.ioffe.ru S.V. Senkevich - Dr.Sc. (Phys.-Math.), Research Scientist, Russian State Pedagogical University. A. I. Herzen (St. Petersburg). Е-mail: SenkevichSV@mail.ioffe.ru I.P. Pronin - Dr.Sc. (Phys.-Math.), Senior Research Scientist, Russian State Pedagogical University. A. I. Herzen (St. Petersburg). Е-mail: Petrovich@mail.ioffe.ru

Backscattering electron nanoscale diffraction is used to detect monoclinic phase in ferroelectric thin films of lead zirconate titanate PZT, the compositions of which correspond to the practically significant region of morphotropic phase boundary (MPB). PZT thin films were prepared by two-stage technology. In the first stage, PZT layers of Zr/Ti = 54/46 composition were deposited on a «cold» substrate Pt/SiO2/Si using RF magnetron sputtering, and at the second one were annealed in air or in a lead atmosphere at 530-650 °C. Elemental composition of the layers was revealed using scanning electron microscopy (EVO-40, Zeiss), equipped with energy dispersive X-ray analyzer INCA. To scan the composition of PZT layer the working gas pressure was varied from 2-8 Pa, allowing to vary layers composition in the concentration range of Zr/Ti = 55/45-52,5/47.5, corresponding to a region MPB. The physical model is suggested, in according to which the atomic ratio Zr/Ti and content of the lead atoms may be strongly changed during magnetron sputtering. Determination of the monoclinic phase (also available other phases in the surface nanolayers PZT thickness of about 10 lattice constants) was carried out by computer-aided comparison (overlay) obtained diffraction patterns with similar patterns from the database ICSD (Inorganic Crystal Structure Database), deciphering the crystal parameters is carried out on the basis of the results of measurements of the neutron and X-ray diffraction for the solid solution composition PZT, close to the investigated. The phase analysis of the results indicates the presence of two modifications of the ferroelectric phase  monoclinic and tetragonal, the ratio of which depends on a number of factors such as the content of lead atoms, the ratio of atoms of Zr/Ti, the annealing temperature of the films, the temperature of the samples. The paper presents a discussion of the laws.

 

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