Piezo element comprises a base body that is made of lead free piezoceramic, comprises regions having different phase transition temperatures, and has monotonic rising gradient of phase transition temperature along preferred direction

摘要

The piezo element (10) comprises a base body made from a lead free piezoceramic such as sodium potassium niobate (K(0.5)Na(0.5)NbO 3), where the base body comprises regions (12, 14, 16) having different phase transition temperatures. The regions having different phase transition temperatures: consist of differently doped K(0.5)Na(0.5)NbO 3; are doped with compositions of rare earth elements; and form a 2-2-composite, a 3-3-composite, a 1-3-composite or 0-3-composite in the base body. The base body has a monotonic rising gradient of the phase transition temperature along a preferred direction. The piezo element (10) comprises a base body made from a lead free piezoceramic such as sodium potassium niobate (K(0.5)Na(0.5)NbO 3), where the base body comprises two regions (12, 14, 16) having different phase transition temperatures. The regions having different phase transition temperatures: consist of differently doped K(0.5)Na(0.5)NbO 3; are doped with various amounts and substance compositions of rare earth elements; and form a 2-2-composite, a 3-3-composite, a 1-3-composite or a 0-3-composite in the base body. The base body further comprises a monotonic rising gradient of the phase transition temperature along a preferred direction. The piezo element is designed as a multilayer structure with inner electrodes (18) that comprise the regions having different phase transition temperatures. An independent claim is included for a method of manufacturing a piezo element.