Morphology of PZT-PMN films grown from airflow
2003 (English)In: Integrated Ferroelectrics, ISSN 1058-4587, Vol. 54, 575-584 p.Article in journal (Refereed) Published
Lead zirconate titanate-lead magnesium niobate (PZT-PMN) films with thicknesses in the range 5 to 200 mum were fabricated by deposition from airflow at room temperature. Precursor powders of PZT and PMN were mixed in a ball mill and entrained in an airflow generated by a commercial jet-mill ( Micron-Master 02-506 ). Films were grown at a rate of 1 mum/minute onto the Ni and tungsten carbide substrates exposed to the air-powder mixture. Unfired, poled PZT-PMN films provided an audio acoustic response and form translucent 20-30 mum thick layers. Full density of the air-flow deposited materials has been achieved at temperatures 450degreesC lower than that typical for ball milled bulk PZT-PMN ceramics. After sintering for 2 hours at 850degreesC PZT-PMN ceramics with relative density of 99.5%, epsilon similar to 2170, tan delta similar to 0.009 @1 kHz and acceptable piezoelectric properties was obtained. Films sintered 2 hours at 1000degreesC showed remnant polarization P-r = 26 muC/cm(2) , P-s = 36 muC/cm(2) @95 kV/cm, and 50 Hz ac electric breakdown field as high as 120-170 kV/cm. Unusual grain morphology governs improved sinterability and enhanced properties of ferroelectric ceramics. Optical and AFM micrographs revealed needle-like grains preferentially oriented parallel to the air-powder stream. As-deposited films were found to be very non-uniform across the thickness: glass-like and with tensile strain on the contact surface. This strain is released and film microcrystalline structure becomes uniform in annealed film.
Place, publisher, year, edition, pages
2003. Vol. 54, 575-584 p.
piezoelectric ceramics, powder charged air-flow, AFM, preferential grain orientation, low temperature synthesis
IdentifiersURN: urn:nbn:se:kth:diva-23052ISI: 000187625200008OAI: oai:DiVA.org:kth-23052DiVA: diva2:341750
QC 201005252010-08-102010-08-10Bibliographically approved