Orientation dependence and electric-field effect in the relaxor-based ferroelectric crystal(PbMg1/3Nb2/3

Abstract

Dielectric permittivities, polarization-electric-field hysteresis loops, and domain structures have been measured as a function of temperature in relaxor-based ferroelectric single crystals (PbMg 1/3 Nb 2/3 O 3 ) 0.68 (PbTiO 3 ) 0.32 ͑PMN-32%PT͒ for ͗110͘ cub and ͗211͘ cub orientations. Contrary to the pure PbMg 1/3 Nb 2/3 O 3 ͑PMN͒, PMN-32%PT exhibits apparent crystallographic orientation dependences of dielectric permittivities, polarizations, domain structures and phase transitions. With a prior field-cooled treatment, a field-induced state, perhaps of orthorhombic symmetry, is evidenced and coexists with the rhombohedral symmetry in the low-temperature region. This field-induced phase is manifested by an extra dielectric peak observed near 373 K for the ͗211͘ cub orientation. A relaxation mechanism which is responsible for the so-called diffuse phase transition crosses a wide temperature region of ϳ340-400 K and results from fluctuations between rhombohedral and tetragonal states. In order of increasing temperature ͑without a prior field-cooled treatment͒, PMN-32%PT undergoes successive phase transformations: rhombohedral phase→coexistence of rhombohedral and tetragonal phases→tetragonal phase→coexistence of tetragonal and cubic phases→cubic phase.

CdS quantum dots: growth, microstructural, optical and electrical characteristics

“…10, which indicates that this compound has semiconductor-like behavior in the temperature range of 10-300 K. The DC resistivity is found to be in the range of 10 10 Ω cm. The high resistivity is consistent with that reported in the literature [51,52]. Materials with smaller crystallite size contain relatively larger volume fraction in between the crystallites, which act as a barrier for current conduction and results in an increase in the resistivity.…”

Domain orientation imaging of PMN–PT single crystals by vertical and lateral piezoresponse force microscopy

“…The relaxor ferroelectric Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PMN-PT) (or Pb(Zn 1/3 Nb 2/3 )O 3 -PbTiO 3 , PZN-PT) single crystals with the composition near the morphotropic phase boundary (MPB, 35% PT in the former, and 9.5% PT in the latter) are currently under investigation due to their excellent electromechanical properties [1][2][3][4][5][6][7][8][9][10]. For the rhombohedral PMN-PT and PZN-PT crystals, though the spontaneous polarization lies in /1 1 1S direction, the superior properties appear in /0 0 1S poled direction with extremely high piezoelectric effect (piezoelectric coefficient up to 2500 pm/V), electric field induced large strain (up to 1.7%) and very high coupling coefficients (up to 95%) [2], which may revolutionize some applications in medical ultrasonic imaging, telecommunication and ultrasonic devices [1].…”

Study of ordered nano‐regions in Pb(Zn1/3Nb2/3)0.915Ti0.085O3 single crystal using Raman spectroscopy

“…The coexistences of rhombohedral/tetragonal and tetragonal/cubic phases have been seen in PMNT samples by using a polarized microscope and other experiments. 17 One might argue that Pb(Zn 1/3 Nb 2/3 0.915 Ti 0.085 O 3 possibly undergoes successive phase transformations: rhombohedral ! coexistence of rhombohedral and tetragonal !…”