Polarization Switching of and Electron Emission from Lead Lanthanum Zirconate Titanate Ceramics

This paper focuses on understanding the influence of ma-terial properties on the complicated ferroelectric (FE) emis-sion process. Three different compositions in the lead lan-thanum zirconate titanate (PLZT) system were chosen for study, based on their widely different dielectric and ferro-electric properties: antiferroelectric (AFE) 2/95/5, “nor-mal” ferroelectric 8/65/35, and nonferroelectric 15/65/35. Repeatable emission was obtained from the 2/95/5 compo-sition, which could also be modulated at high frequency (200 kHz). the fast AFE ⇆ FE phase transition is respon-sible for the FE emission properties of this material, which is supported by the relationship between the switching cur-rent and the emission current. Comparatively, FE emission from the 8/65/35 composition degraded rapidly, which was attributed to decreases in the remanent polarization. No emission signal was detected from the 15/65/35 composi-tion, because no switching activity occurs, which can be interpreted as additional evidence that electron emission from the previously mentioned two compositions was in-deed a FE emission process