Studies of the unipolarity arising in the non-poled ferroelectric ceramics with electrodes from different metals on the opposite sides

ABSTRACT

Application of electrodes from metals with different coefficients of linear thermal expansion on the opposite surfaces of non-poled plates of ferroelectric PZT-19 ceramics leads to formation of stationary gradients of mechanical strain and stresses in the samples. As a result, electric response to three-point mechanical loading, pyroelectric and piezoelectric responses, asymmetry of the polarization hysteresis loop (internal electric field), as well as the nonuniform distribution of the surface potential in the interelectrode space were observed. Unipolarity did not destroy after multiple heating and cooling cycles up to 400°C, i.e. well above the Curie temperature.

KEYWORDS:

• Ferroelectric ceramics
• piezoelectric response
• pyroelectric effect
• unipolarity

Funding

The work was supported by the Ministry of Science and Education of the Russian Federation (project № 3.1649.2017/4.6).