Large piezoelectric response in a family of metal-free perovskite ferroelectric compounds from first-principles calculations

• DOI: 10.1038/s41524-019-0157-4
• Publication Date: 2019-02-06T11:04:47Z
• Authors: Hui Wang; Huihui Liu; Zeyu Zhang; Zihan Liu; Zhenlong Lv; Tongwei Li; Weiwei Ju; Haisheng Li; Xiaowu Cai; Han Han
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract Metal-free organic perovskite ferroelectric materials have been shown recently to a number of attractive properties, including high spontaneous polarization and piezoelectric coefficients. In particular, slow evaporation solutions containing amines, inorganic ammoniums, dilute hydrohalogen acid has produce several in the MDABCO-NH 4 -I 3 family (MDABCO is N-methyl-N’-diazabicyclo[2,2,2] octonium). present work, we study by first-principles calculations origin polarizaiton, electronic density state, response, elastic properties -X (X = Cl, Br, I). We find that dipole moments MDABCO NH groups are negligible, large mainly results from being off-center relative I ions. Although response usually very weak, observe strain components, d x 5 ; calculated 119 pC/N for -Cl , 248 -Br 178 . The value found be closely related with compliance tensor, s 44 These show metal-free perovskites soft properties.