Title :
Novel ferroelectricity in polar semiconductor ZnO by Li-substitution
Author :
Onodera, A. ; Tamaki, N. ; Yoshio, K. ; Satoh, H. ; Takama, T. ; Yamashita, H.
Author_Institution :
Dept. of Phys., Hokkaido Univ., Sapporo, Japan
Abstract :
Ferroelectricity in Li-substituted II-VI semiconductor ZnO ceramics was studied. A ferroelectric phase transition temperature Tc is 370 K in hot-pressed ceramics synthesized by the spark plasma sintering method, although the previous cold-pressed ceramics showed a relative low Tc (330 K). The Rietveld analysis of X-ray powder diffraction pattern showed RWP=7.4%, u=0.3821 (3) for Zn (Li) and x=0.09 at 293 K in Zn1-xLixO hot-pressed ceramics. The ferroelectricity in Zn1-xLix O results from small structural distortion (of order 10-3 Å) induced along the polar c-axis by substitutional Li atoms, instead of the host Zn atoms in the wurtzite structure
Keywords :
II-VI semiconductors; crystal structure; ferroelectric Curie temperature; ferroelectric ceramics; ferroelectric semiconductors; hot pressing; lithium compounds; sintering; wide band gap semiconductors; zinc compounds; 470 K; Li-substituted II-VI semiconductor ZnO ceramics; Li-substitution; Rietveld analysis; Tc; X-ray powder diffraction pattern; Zn1-xLixO hot-pressed ceramics; ZnLiO; ZnO; cold-pressed ceramics; ferroelectric phase transition temperature; ferroelectricity; hot-pressed ceramics; polar c-axis; polar semiconductor; spark plasma sintering method; structural distortion; wurtzite structure; Ceramics; Conductivity; Dielectrics; Ferroelectric materials; Physics; Plasma temperature; Powders; Sparks; X-ray diffraction; Zinc oxide;
Conference_Titel :
Applications of Ferroelectrics, 1998. ISAF 98. Proceedings of the Eleventh IEEE International Symposium on
Conference_Location :
Montreux
Print_ISBN :
0-7803-4959-8
DOI :
10.1109/ISAF.1998.786735
