摘要
Most piezoelectric materials exhibit a positive longitudinal piezoelectric effect(PLPE),while a negative longitudinal piezoelectric effect(NLPE)is rarely reported or paid much attention.Here,utilizing firstprinciples calculations,we unveil the origin of negative longitudinal piezoelectricity in ferroelectric hafnia by introducing the concept of weighted projected bond strength around cation in the c direction(WPBc),which is proposed to quantitatively characterize the asymmetric bonding stiffness along the strain direction.When the WPBc is anti-parallel to the direction of bulk spontaneous polarization,the polarization decreases with respect to tensile strain and leads to a negative piezoelectricity.
基金
supported by the National Natural Science Foundation of China(52072240)
the Shanghai Technology Innovation Action Plan 2020-Integrated Circuit Technology Support Program(Project No.20DZ1100603).
