Absence of auxeticity in CoFe2O4 epitaxial films. (1st July 2022)

• Record Type: Journal Article
• Authors: Jiang, Yitian; Li, Xingxing; Zhang, Xingwang; Cheng, Yong; Zhang, Ling; Dong, Hao; Yin, Zhigang; Zhang, Xin
• Is Part Of: Japanese journal of applied physics. Volume 61:Number 7(2022)
• Publication Date: 2022-07-01
• Subjects: auxetic materials -- epitaxial lift-off -- poisson ratio -- spinel ferrites -- domain matching epitaxy -- strain -- flexible oxide films; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/ac759b
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We report the absence of auxeticity in CoFe2 O4, a magnetic spinel oxide. A CoFe2 O4 (111) epilayer was grown on the ZnO sacrificial layer, and the in-plane and out-of-plane lattice parameters were precisely determined by X-ray reciprocal space maps. To block the influence from stoichiometry variations, the same CoFe2 O4 epilayer was lifted off from the substrate and was used as the reference sample. No auxetic behavior was found, and a positive Poisson ratio of ∼0.32 was obtained. Moreover, the Poisson ratio derived from the compliance coefficients agrees well with our experimental observation.