Processing and Dielectric Properties of Sol-Gel Derived PMN-PT (68:32) Thin Films

Abstract

PMN-PT thin films near MPB were prepared using sol-gel technique. A transparent solution of the ceramic was prepared by using lead acetate trihydrate, magnesium ethoxide, niobium ethoxide and titanium isopropoxide as precursors along with 2methoxyethanol as solvent and acetic acid as catalyst. Thin films of the ceramic were prepared on Pt/Si and on ITO coated glass substrates. X-ray diffraction (XRD) studies show the formation of perovskite phase of the films with less than (5%) pyrochlore phase. Scanning electron microscopy (SEM) study of the films on different substrates show well developed grains of sub-micron size. Dielectric constant measurement at different temperature was carried out. Room temperature value of dielectric constant and dielectric loss at 1 kHz of the ceramic thin films on ITO coated glass and Pt/Si substrates were found to be 500, 0.03 and 415, 0.01 respectively. Dielectric measurements for different thicknesses of the films have also been carried out. P-E loop and I-V studies of the films were also carried out.

Ferroelectric thin films with complex composition of PNN–PZN–PMN–PZ–PT and excess NiO

“…4,6,8,15,16 However, properties of the resulting films depend on the nature of precursor solution, deposition condition, and the substrate. 4,6,8,15,16 However, properties of the resulting films depend on the nature of precursor solution, deposition condition, and the substrate.…”

Synthesis of perovskite electrooptic thin films by polymer modified sol-gel processing

“…The dielectric constant obtained here is significantly higher than the 1000-1600 obtained by pulsed laser deposition, 35,36,37 or the other sol-gel processing techniques. 38,39 Temperature Similar -T response with T max =110-120°C has also been reported in the sol-gel derived PMN-PT films by Park et al 40 and Calzada et al 41 The extent of diffusiveness for the -T curves can be evaluated by using the modified Curie-Weiss equation as below:…”

“…38 The films epitaxially grown on (100)-cut LaAlO3 (LAO) substrates exhibited a slightly higher EO coefficient of ~1.6x10 -16 (m/V) 2 . 39,40 PT content, electric field direction and multi-layer structure of the films, are the factors affecting the EO properties of the PMN-PT films. Figure 2-9 also shows the applied electric-field direction exerting much influence on the measured EO coefficients.…”

“…When the electric field was applied along in-plane <110>, at least two times larger in magnitude of EO effect was found compared with those along in-plane <001>. 39,40 Meanwhile, it is also noted that an EO superlattice structure composing of alternative PMN-PT rhombohedral ( x PT =0.40) and tetragonal phases (x=0.26) can remarkably enhance the EO coefficients. Figure 2-10 shows the dependence of both in-plane and out-of-plane EO coefficients on the periodicity of the EO superlattice structure.…”

“…9 shows that the in-plane quadratic EO coefficient of the films increases significantly when the compositions are close to MPB and reaches maximum when the PT content x=0.33 39. …”