Search

Single crystals and ceramics of (1- x )PMN– x PT were synthesized in the whole concentration range from x =0 to x =1, and the temperature-concentration phase diagram of the system was determined fr...

The behavior of domain reversal in relaxor Pb(Zn 1/3 Nb 2/3 )O 3 single crystals was studied using X-ray diffraction measurements. After the electric field was switched instantaneously, the {222} B...

PbIn 1/2 Nb 1/2 O 3 (PIN) single crystal plates obtained by different thermal treatment were investigated by means of polarizing microscopic observations. It was found that, in an as-grown PIN (cal...

The pressure dependence in the disordered Pb(In 1/2 Nb 1/2 )O 3 (PIN) single crystals (S=0.4 (type(I)), 0.2 (type(II))) were investigated by X-ray diffraction. The pressure dependence of the cell p...

The phase transition under pressure up to 1 GPa in a relaxor-Pb(In 1/2 Nb 1/2 )O 3 (PIN) single crystal was investigated by X-ray diffraction. With increasing applied pressure, the integrated inten...

Dielectric properties of the disordered and ordered Pb(In 1/2 Nb 1/2 )O 3 (abbreviated as PIN) single crystals were investigated in the range of temperature T from -70 to 200°C and of hydrostatic pressures p up to 0.7 GPa. For the disordered PIN, a typical dielectric dispersion which obeys the empirical Vogel-Fulcher relation was observed. Such dielectric dispersion strength was weakened with an increase in the degree of chemical ordering (S) at the B-site cations in the perovskite ABO 3 , and then relaxor behavior disappears. The relaxor behavior was also weakened with increasing pressure up to 0.7 GPa for the quenched disordered PIN with S=0.2, whereas for the disordered PIN with S=0.4, the relaxor behavior was weakened with increasing pressure and then the antiferroelectric phase transition was induced by the application of pressure above 0.4 GPa. For the ordered PIN, the phase below the transition temperature was confirmed to be antiferroelectric by observation of P - E double hysteresis loops. The st...

Ordered (S=0.8) and disordered (S=0) crystals of PbIn 1/2 Nb 1/2 O 3 (PIN) were investigated by X-ray diffraction measurement in the temperature range of 20 K to 580 K. The ( h /4 k /4 0) superlattice reflection for the ordered antiferroelectric sample and the ( h h h ) fundamental reflection for the disordered ferroelectric sample were measured for evaluation of the temperature dependence of their order parameters. The ( h /2 k /2 0) (α-spots) and the ( h /2 0 0) (β-spots) superlattice reflections were also observed. The temperature dependence of the integrated intensity of the α-spot was compared with that of the ( h /4 k /4 0) reflection in both samples. Their reflections showed the same temperature dependence. The origin of the α-spots is due to the antiferroelectric distortion. The temperature dependence of the integrated intensity of the α-spot of the ordered sample was different from that of the disordered sample. The differences were explained by a size effect of the clusters.

The dielectric properties of Pb(In 1/2 Nb 1/2 )O 3 (abbreviated as PIN) single crystal were investigated under hydrostatic pressures up to 0.7 GPa. The ordered PIN was confirmed to be antiferroelectric by observation of clear P - E double hysteresis loops below the transition temperature. There is a striking pressure effect in the disordered PIN. The relaxor behavior becomes less notable with increasing pressure and disappears at 0.4 GPa. At pressures above 0.4 GPa, the normal phase transition without dielectric dispersion in the low frequency range takes place and with increasing pressure, the temperature T m , indicating the maximum of the dielectric constant, e rm ′ , increases at a rate of 150 K/GPa and the e rm ′ decreases. Such dielectric phenomena with pressure are similar to those observed in antiferroelectric PbZrO 3 .

The ferroelastic behavior of relaxor 24Pb(In1/2Nb1/2)O3–46Pb(Mg1/3Nb2/3)O3–30PbTiO3 (PIN–PMN–PT) solid-solution single crystals was investigated under shear stresses using polarization light microscopy (PLM) and the scanning electron microscopy (SEM). Optical strain patterns along the \(\{110\}_{\text{cub}}\) directions from the orthoscope images under crossed Nicol, induced by shear stresses applied along the \([001]_{\text{cub}}\) direction, making use of a Vickers microindenter with a square-base diagonal line oriented along the \(\{100\}_{\text{cub}}\) directions of the crystal were observed on its \((001)_{\text{cub}}\) plate for the first time. These patterns at a diagonal position reveal a flowerlike pattern for ferroelastic transition from a square (S) lattice to a rectangular (R) lattice in a two-dimensional model system. A change in the interference color from yellow to blue through red toward the center in their flower leaves, according to the Michel–Levy birefringence chart, was observed. The ...

Structural properties of as-grown Pb(In 1/2 Nb 1/2 )O 3 (PIN) single crystals at room temperature (RT) were investigated by x-ray and neutron scattering techniques, taking much account of the diffe...

The relative permittivity ( e r ) and dielectric conductivity (σ) of RbNO 3 single crystals were measured at 1 MHz under hydrostatic pressures over its two phase transformations; II-III (219°C at l aim) and III-IV (164°C at 1 atm). The value of e r has a large peak at the II-III phase transition pressure, and 1/ e r obeys the Curie-Weiss law on pressure in the phase III. This behavior of e r is elucidated by the phenomenological theory for the first order antiferroelectric phase transition. The II-III phase boundary was determined by the dielectric measurement. At the IV-III phase transition temperature ( T c ), the changes in e r and σ seen in the e r vs. T and σ vs. T curves get smaller with increasing applied-pressure. The behavior of e r and σ is explained by taking account of the rotation of NO 3 - ions being hindered by the pressure.

Pressure-temperature phase diagrams of {N(CH 3 ) 4 } 2 CoCl 4 and {N(CH 3 ) 4 } 2 ZnCl 4 were studied by means of dielectric measurements in the temperature and pressure region of -180∼50°C and 0∼2.0 kbar. Phases of Co- and Zn-salts are classified in a single pressure-temperature phase diagram; phases I, II, III, IV, V, VI and VII in Co-salt coincide with phases I, II, III, VII (pressure-induced), IV, V and VI in Zn-salt, respectively, by considering that the applied pressure p =0 bar (=1 bar) onto Co-salt corresponds to the p =550 bar to Zn-salt. The pressure coefficients of IV–V and V–VI phase transition temperatures in Zn-salt have extremely large values of d T i v - v /d p =50±3°C/kbar and d T v - v i /d p =-54±3°C/kbar, respectively.

Effects of hydrostatic pressure on the phase transition points of ferroelectric NH 4 LiSO 4 were studied by dielectric measurements at 1 kHz over a temperature range of 0∼210°C and a pressure range up to 2 kbar. The observed pressure coefficients of I–II and II–III phase transition temperatures (186.5°C and 10°C at 1 atm, respectively) were 9.8 deg/kbar and -3.3 deg/kbar, respectively.