Upconversion luminescence, ferroelectrics and piezoelectrics of Er Doped SrBi4Ti4O15

Abstract

Er3+ doped SrBi4Ti4O15 (SBT) bismuth layered-structure ferroelectric ceramics were synthesized by the traditional solid-state method, and their upconversion photoluminescent (UC) properties were investigated as a function of Er3+ concentration and incident pump power. Green (555 nm) and red (670 nm) emission bands were obtained under 980 nm excitation at room temperature, which corresponded to the radiative transitions from 4S3/2, and 4F9/2 to 4I15/2, respectively. The emission color of the samples could be changed with moderating the doping concentrations. The dependence of UC intensity on pumping power indicated a two-photon emission process. Studies on dielectric properties indicated that the introduction of Er increased the ferroelectric-paraelectric phase transition temperature (Tc) of SBT, thus making this ceramic suitable for piezoelectric sensor applications at higher temperatures. Piezoelectric measurement showed that the doped SBT had a relative higher piezoelectric constant d33 compared with the non-doped ceramics. The thermal annealing behaviors of the doped sample revealed a stable piezoelectric property. The doped SBT showed bright UC emission while simultaneously having increased Tc and d33. As a multifunctional material, Er doped SBT ferroelectric oxide showed great potential in application of sensor, future optical-electro integration and coupling devices

Piezoelectric properties and thermal stabilities of strontium bismuth titanate (SrBi4Ti4O15)

“…To improve the piezoelectric performance of SBT ceramics, the piezoelectric properties of metal oxides modified SBT ceramics have been investigated extensively. For example, the Dy-modified SBT (SBT-Dy) has a piezoelectric constant d 33 value of 17 pC/N [25], the Er-modified SBT (SBT-Er) shows a d 33 value of 16 pC/N [26], and the Ho-modified SBT presents a d 33 value of 15 pC/N [27]. These results revealed that the rare-earth oxides can enhance the piezoelectric properties of SBT ceramics.…”

Effect of Ba2+ substitution on the structural and electrical properties of SrBi4Ti4O15 ceramic

“…This result is consistent the ferroelectric properties of the above material. It can be seen that the piezoelectric constant (d 33 ) were increased in all the modified compounds in comparison with the pure SrBi 4 Ti 4 O 15 .…”

“…Higher concentration of Ba 2+ substitution may give the diffuse phase transition in this system. lower c-axis ratio shows better saturated hysteresis loop than that with higher c-axis ratio due to weak ferroelectricity or higher conductivity in bismuth layered ferroelectric along c-axis [33].…”

“…For piezoelectric measurement the pellets were poled at 120°C by applying a DC electric field of 8kV/mm for 30 min. The piezoelectric coefficient (d 33 ) was measured using a piezoelectric d 33 -meter (ZJ-4NA).The remanent polarization was determined from a P-E hysteresis loop measurement using a Sawyer 2000 FE-Module ferroelectric tester.…”

“…Recently, these bismuth layer-structured materials with m=4 have been intensively investigated as lead-free ferroelectric as well as piezoelectric materials. Out of them the four layer SrBi 4 Ti 4 O 15 is a prominent candidate for high temperature piezoelectric applications due to its high Curie temperature (T c~ 530°C) but the d 33 value is comparatively less than that of lead based system [8]. It has orthorhombic symmetry with space group A 21 am at room temperature and transforms to tetragonal space group I4/mmm above the transition temperature [9].…”