Ferroelectrics, 459:32–37, 2014 Copyright © Taylor & Francis Group, LLC ISSN: 0015-0193 print / 1563-5112 online DOI: 10.1080/00150193.2013.837753 Study of the Factors Affecting the Mechanical, Electrical, and Piezoelectric Properties of PZT Micro-Actuator PUNTIPA SUAPRASERT, 1,3 PAVADEE AUNGKAVATTANA, 2 AND PATAMAS BINTACHITT 1,* 1 Faculty of Science, Srinakharinwirot University, Thailand 2 National Metal and Materials Technology Center (MTEC), Thailand Science Park, Thailand 3 Western Digital (Thailand) Co. Ltd. The durability, the reliability and the factors leading to the degradation of PZT become more important. The factors initiating the degradation such as crack propagation and environmental conditions were investigated. The dielectric constant and the piezoelec- tric coefficient, d 31 of PZT prior to degradation are 3200 and 15000 pm/V, respectively. After the degradation with crack propagation, the dielectric constant and piezoelec- tric coefficient, d 31 were reduced to 3100, 2400, 1400 and 12000, 11000, 349 pm/V, respectively depend on the degree of crack propagation. In addition, the effect of envi- ronmental conditions such as temperature of un-cracked and pre-cracked samples were also investigated and reported. Keywords PZT micro-actuator; piezoelectric properties; crack; degradation; HDDs 1. Introduction Lead zirconate titanate (PZT) ceramic has superior piezoelectric and ferroelectric properties due to its large piezoelectric effect. PZT piezoelectric materials have been used as micro- sensors and micro-actuators in many applications such as energy harvesting, biomedical diagnostic tools, and hard disk drive. At present, the electronic devices especially hard disk drives (HDDs) tend to be small size with outstanding functionality and low cost. The HDDs technology has developed rapidly to have higher capacity with achieving cost reduction and areal density from year to year [1–4]. Nowadays, the PZT micro-actuator has been proposed as secondary actuators in HDDs technology for improving the track-per-inch (TPI), servo performance, and read/write head positioning control system [5]. However, PZT piezo- electric ceramic can be degraded due to its brittleness. Degradations of PZT ceramics are important for reliability issues. There are many possible factors affecting the degradation of piezoelectric ceramic such as fatigue, composition, frequency, stress, temperature, hu- midity, micro-crack, electric field, and microstructure, etc. [6–9]. The PZT micro-actuator can be easily degraded during the assembly process due to its ceramic characteristics and environmental conditions. All factors and the degradation of piezoelectric properties are Received December 11, 2012; in final form March 8, 2013. * Corresponding author. E-mail: patamas@swu.ac.th [1444]/32 Downloaded by [Srinakharinwirot University] at 21:24 28 January 2014