Modified structural, optical, magnetic and ferroelectric properties in (1-x)BaTiO3-xBaCo0.5Nb0.5O3-δ ceramics. Issue 5 (1st April 2020)

• Record Type: Journal Article
• Authors: Zheng, Dongliang; Deng, Hongmei; Si, Shufang; Pan, Yanlin; Zhang, Qiao; Guo, Yixin; Yang, Pingxiong; Chu, Junhao
• Is Part Of: Ceramics international. Volume 46:Issue 5(2020)
• Page Start: 6073
• Page End: 6078
• Publication Date: 2020-04-01
• Subjects: Phase transition -- Optical properties -- Ferroelectric ceramics -- Perovskites; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.11.068
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Lead-free perovskite ceramics with the formula of (1- x )BaTiO3 - x BaCo0.5 Nb0.5 O3-δ ((1- x )BT- x BCN), exhibit structural phase transition, modified band-gap ( E g ), ferromagnetic and ferroelectric orders at room-temperature (RT). All ceramics have no impurity phase but the structural transition from tetragonal to cubic phase is observed with the increase of x . A possible mechanism is proposed to explain the variation of crystal structure. Raman scattering analysis not only proves the existence of doping-induced phase transition but also indicates the changed bonding vibration modes between adjacent atoms. The appearance of two band-gaps in doping samples, the low E g is about 1.3 eV, obviously smaller than that of 3.2 eV for pure BaTiO3 (BT), which is attributed to the electronic orbital of Co 3 d within the gap of BT. Moreover, the RT ferromagnetic behavior is obtained at x = 0.05, which can be interpreted via the F center exchange model. These results show the potential applications for perovskite oxides on solar energy conversion apparatus and multiferroic devices.