Lead-free piezoelectric system (Na0.5Bi0.5)TiO3-BaTiO

Tuning Photoluminescence Response by Electric Field in Electrically Soft Ferroelectrics

“…Such a scenario does exist in electrically and elastically soft ferroelectrics in the proximity of a ferroelectric instability. The electromechanical softness of the lattice, in conjunction with the strong coupling of polarization with crystal structure, makes such systems amenable to field induced structural transformation [4][5][6][7][8][9][10][11][12][13]. The consequent change in the crystal field parameters is expected to affect the PL response of doped emitter ions, such as the rare earth ions, if they are embedded in such a ferroelectric host.…”

“…Subsequent studies reported that the critical composition exhibits cubic structure [17], and the hetrophase ferroelectric state appears only after application of strong electric field, i.e. poling [13,16,18]. In view of the drastic effect of electric field on this system, we chose NBT-6BT as a model host for investigating the effect of electric field on the PL response.…”

Anomalous change in leakage and displacement currents after electrical poling on lead-free ferroelectric ceramics

“…[1][2][3] Over the last five decades, the effect of electrical poling on dielectric properties of (1 À x) (Na 0.50 Bi 0.50 )TiO 3 -xBaTiO 3 (NBT-BT) has been studied in detail, most interesting observations are as follows: stabilization of long-range order and reduction of tilt disorder through compositional tunings, reduction of structural inhomogeneities, conversion of non-ergodic relaxor phase to a long-range polar phase, transformation of stripe-like unpoled nanodomains to lamellar tetragonal domains, switching of an antiferroelectric nonpolar to a ferroelectric polar state, improved piezo and ferroelectric properties under combined electrical and mechanical poling. [4][5][6][7][8][9][10] However, the detailed microscopic conduction mechanisms before and after poling, particularly for the dia-, tri-, and tetra-valent cations substituted systems remain missing so far.…”

“…[4][5][6][7][8][9][10][11][12] The application of E-fields for a minimum exposure time is the most accepted procedure to get stable polarization. The best way to achieve the stable polarization in minimum time is heating of polar electroceramics to near T c and poled it for few hours (h) below the coercive field; in this situation, the coercive field is very low compared to the normal values and therefore easy to pole.…”

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

“…By means of TEM, Lee et al 365 discovered the presence of ( − − − ) octahedral tilting 146,377 supporting the presence of a 3 symmetry for ST contents below 30 mol % ST. With increasing temperature, a gradual decrease of the unit cell distortions was found from a monotonic decrease of Raman modes. The high temperature phase was reported to be cubic for the whole compositional range investigated in Figure 3.9; however, the presence of Raman activity indicates that the local structure of the system remains distorted.…”