HE Xuan ¹, DU Zhenbo ^1,3, FAN Shangqing ^1,3, ZENG Renjie ^1,2

(1. College of Materials, Xiamen University, Xiamen, Fujian 361005, China; 2. Fujian Provincial Key Laboratory of Advanced Materials, Xiamen, Fujian 361005, China; 3. Parkathings Amorphous Materials Technology Co., Ltd.,Xiamen, Fujian 361101)

Abstract: Glass-ceramics of ZnO－Bi₂O₃ －B₂O₃ system doped with La₂O₃ were prepared by sintering method and were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectrum analyzer, X-ray diffractometry (XRD),dilatometer (DIL) and HP automatic bridge (LCR). The relationships the content of La₂O₃ with the structure, crystallization thermal expansion coefficient (α), dielectric constant (εr), and dielectric loss (tanδ) of the glass ceramics are investigated.The results show that doping 0~2.0 wt.% La₂O₃ can significantly inhibit crystallization, decrease εr and tanδ. La₂O₃ addition can significantly help Bi₂O₃ enter the network structure. with the La₂O₃ addition increasing, the α of the glass changes like the letter "N"; the number of [BiO₃], [BiO₆] and isolated triangular orthoborate units firstly increases and then slightly decreases.When the content of La₂O₃= 1.5 wt.%, the number of these units and the α reach their maximum.

Key words:  rare-earth; lead-free; low softening temperature; crystallization