Sk. Mishra et D. Pandey, THERMODYNAMIC NATURE OF PHASE-TRANSITIONS IN PB(ZRXTI1-X)O-3 CERAMICSNEAR THE MORPHOTROPIC PHASE-BOUNDARY .2. DIELECTRIC AND PIEZOELECTRICSTUDIES, Philosophical magazine. B. Physics of condensed matter. Statistical mechanics, electronic, optical and magnetic, 76(2), 1997, pp. 227-240
From a study of the temperature dependence of the dielectric constant
of Pb(ZrxTi1-x)O-3 the ferroelectric transition for 0.515 less than or
equal to 0.535 is shown to be discontinuous in nature while it is con
tinuous for x = 0.550. It is proposed that there may be a tricritical
point around x = 0.545. The two-phase nature of the morphotropic phase
boundary (MPB) has been confirmed from the temperature dependence of
the resonance frequency. The temperature variation in the planar coupl
ing coefficient k(p) is correlated with structural changes to show tha
t the maximum k(p) at a given Zr concentration x is a function of temp
erature T and occurs in the tetragonal phase field just outside the tw
o-phase MBP region in the (x,T) plane.