| Giant room-temperature electrostrictive coefficients in lead-free relaxor ferroelectric-ceramics by compositional tuning | |||||
| 작성자 | 김** | 작성일 | 2018-09-05 | 조회수 | 376 |
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Journal Article published Jan 2018 in APL Materials volume 6 issue 1 on page 016104
Authors: Aman Ullah, Hafiza Bushra Gul, Amir Ullah, Muhammad Sheeraz, Jong-Seong Bae, Wook Jo, Chang Won Ahn, Ill Won Kim, Tae Heon Kim
A thermotropic phase boundary between non-ergodic and ergodic relaxor phases is tuned in lead-free Bi1/2Na1/2TiO3-based ceramics through a structural transition driven by compositional modification (usually named as “morphotropic approach”). The substitution of Bi(Ni1/2Ti1/2)O3 for Bi1/2(Na0.78K0.22)1/2TiO3 induces a transition from tetragonal to “metrically” cubic phase and thereby, the ergodic relaxor ferroelectric phase becomes predominant at room temperature. A shift of the transition temperature (denoted as TF-R) in the non-ergodic-to-ergodic phase transition is corroborated via temperature-dependent dielectric permittivity and loss measurements. By monitoring the chemical composition dependence of polarization-electric field and strain-electric field hysteresis loops, it is possible to track the critical concentration of Bi(Ni1/2Ti1/2)O3 where the (1 ? x)Bi0.5(Na0.78K0.22)0.5TiO3-xBi(Ni0.5Ti0.5)O3 ceramic undergoes the phase transition around room temperature. At the Bi(Ni0.5Ti0.5)O3 content of x = 0.050, the highest room-temperature electrostrictive coefficient of 0.030 m4/C2 is achieved with no hysteretic characteristic, which can foster the realization of actual electrostrictive devices with high operational efficiency at room temperature. |
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