A random field theory based model for ferroelectric relaxors

A model for ferroelectric relaxors such as PMN, PSN and PLZT giving a quantitative description of their properties and phase diagrams is proposed within the framework of the random field theory. In this model, the relaxors are considered as systems with random sites and orientations of electric dipoles, lattice vacancies, antisite ions and other defects as well as impurities embedded into the paraelectric phase, which is proposed to be the `host' lattice for these materials. The calculations of the temperature which corresponds to the transition from the paraelectric to the ferroelectric phase is carried out as a function of the concentration of lattice defects (point charges and dilatational centres). On the basis of these calculations, the peculiarities of the ferroelectric relaxor phase diagram are discussed. The main features of the phase transition sequence when decreasing the temperature in relaxors with constant dipole and defect concentrations are described. The Cross superparaelectric model and Burns temperature have been shown to appear in a natural way in the proposed model. A comparison between calculated and experimental data has been made for the model ferroelectric relaxor PLZT x/65/35. Fairly good agreements between calculated and measured and critical concentrations of lanthanum have been obtained from the model.

[1]  M. Glinchuk,et al.  Influence of the random elastic fields on the phase transitions in disordered ferroelectrics , 1995 .

[2]  M. Glinchuk.  Phase transitions in disordered ferroelectrics with two types of random site electric dipole , 1995 .

[3]  M. Glinchuk,et al.  Random fields influence on dynamic properties of disordered ferroelectrics , 1995 .

[4]  M. Hrabovsky,et al.  Investigation of chromium impurities charge state and chemical bonds in PLZT ceramic , 1995 .

[5]  D. Viehland,et al.  Polarization switching mechanisms and electromechanical properties of La-modified lead zirconate titanate ceramics , 1995 .

[6]  M. Glinchuk,et al.  Random fields and their influence on the phase transitions in disordered ferroelectrics , 1994 .

[7]  J. Dellis,et al.  A Raman and dielectric susceptibility study of superparaelectric PLZT ceramics , 1994 .

[8]  M. Glinchuk,et al.  Investigation of ion displacements and dynamics in crystal with difused phase transitions by the method of NMR , 1994 .

[9]  L. Jastrabík,et al.  Luminescence and optical absorption in nominally pure and Cr‐doped PLZT ceramics , 1994 .

[10]  D. Viehland,et al.  Dielectric properties of tetragonal lanthanum modified lead zirconate titanate ceramics , 1993 .

[11]  M. Glinchuk,et al.  Dynamic of Nb ions in PMN diffused phase transition region and its NMR investigation , 1993 .

[12]  D. Dimos,et al.  Optically induced absorption and paramagnetism in lead lanthanum zirconate titanate ceramics , 1992 .

[13]  Cross,et al.  Glassy polarization behavior of relaxor ferroelectrics. , 1992, Physical review. B, Condensed matter.

[14]  Westphal,et al.  Diffuse phase transitions and random-field-induced domain states of the "relaxor" ferroelectric PbMg1/3Nb2/3O3. , 1992, Physical review letters.

[15]  J. Gavarri,et al.  A structural model for the relaxor PbMg1/3Nb2/3O3 at 5 K , 1991 .

[16]  G. Rossetti,et al.  X‐ray and phenomenological study of lanthanum‐modified lead zirconate‐titanates in the vicinity of the relaxor phase transition region , 1991 .

[17]  M. Wuttig,et al.  Internal strain relaxation and the glassy behavior of La‐modified lead zirconate titanate relaxors , 1991 .

[18]  J. Gavarri,et al.  X-ray and neutron diffraction studies of the diffuse phase transition in PbMg13Nb23O3 ceramics , 1991 .

[19]  M. Glinchuk,et al.  Dipole glass and ferroelectricity in random-site electric dipole systems , 1990 .

[20]  G. Burns,et al.  Ferroelectrics with a glassy polarization phase , 1990 .

[21]  P. Gaucher,et al.  Modification of the B-site order of PbMg13Nb23O3 ceramics by thermal annealing or by La-doping , 1990 .

[22]  E. Furman,et al.  Thermodynamic theory of the lead zirconate-titanate solid solution system, part I: Phenomenology , 1989 .

[23]  C. Darlington.  On the changes in structure of PLZT (8.7/65/35) between 80 and 750 K , 1989 .

[24]  E. Husson,et al.  Structural study of PMN ceramics by X-ray diffraction between 297 and 1023 K , 1989 .

[25]  C. Darlington.  Transitions in the glassy ferroelectric PLZT (8.7/65/35) , 1988 .

[26]  L. Kamzina,et al.  The peculiarities of optical and photorefractive properties of some non-completely ordered ferroelectrics , 1988 .

[27]  J. Hańderek,et al.  Some electric properties of PLZT ceramics , 1986 .

[28]  Fleury,et al.  Cluster dynamics in a dipolar glass. , 1986, Physical review letters.

[29]  James R. Bolton,et al.  Electron Spin Resonance , 1986 .

[30]  G. Burns,et al.  Crystalline ferroelectrics with glassy polarization behavior , 1983 .

[31]  A. Meitzler,et al.  Polymorphism and penferroelectricity in PLZT ceramics , 1973 .

[32]  Am Stoneham,et al.  Shapes of Inhomogeneously Broadened Resonance Lines in Solids (Invited Talk) , 1969 .