Effect of Nb and more Fe ions co-doping on the microstructures, magnetic, and piezoelectric properties of Aurivillius Bi5Ti3FeO15 phases

Aurivillius Bi5Ti3 −2xFe1+xNbxO15 (BTFNO, x = 0.1, 0.2, 0.3, and 0.4) phases were prepared by solid state reaction method. The structures and dielectric responses were studied, and especially the effects ofNb with a higher valence and more Fe co-doping on the magnetic andpiezoelectricproperties were addressed in detail. The BTFNO samples were well crystallized with no detectable impurities, and plate-likemicrostructures with various sizes demonstrate the typicalcharacteristics of bismuth-layer Aurivilliusmaterials. It is found that a dielectric loss peak appears in theNb and Fe co-doped Bi5Ti3FeO15 (BTFO)ceramics, and it has a shift towards a lower frequency with increasing theNbdoping contents. Furthermore, antiferromagnetic long-range magnetic order is improved with the introduction ofNb and more Fe co-doping. And compared with that of the parent BTFO forms, a clear discrepancy, which is indicative of a super-paramagnetic behavior, of the magnetizationvs. temperature curves in zero-field cooling and field cooling cases is observed by the introduction of theNb and more Feions. More interestingly, the introduction ofNb and more Feions can suppress the preferredc-axis growth while promoting thea-/b-axis growth of the plate-like grains, and thus favors thepiezoelectric behaviors of the BTFO Aurivillius phases along the growth orientation.

Source: Journal of Applied Physics - December 5, 2016 Category: Physics Authors: Chao Chen, Kun Song, Wei Bai, Jing Yang, Yuanyuan Zhang, Pinghua Xiang, Muyang Qin, Xiaodong Tang and Junhao Chu Source Type: research