Photoacoustic analysis of the ferroelectric ceramics specific heat

Abstract

Knowing the thermal expansion of a material and the correlation analysis of the photoacoustic signals, it is possible to obtain the phase transition temperature and a qualitative curve of the specific heat at constant pressure (Cp) for ceramic materials. This analysis was applied to a BaTiO3 ferroelectric ceramic and a good agreement with previously published Cp versus temperature curves was obtained. Additionally, the phase transition temperature and the Cp curve of a samarium-doped lead titanate ceramic (Pb0.88Sm0.08TiO3) are presented. The phase transition temperature of the Pb0.88Sm0.08TiO3 obtained with this technique was corroborated with classical differential thermal analysis and dielectric permittivity measurements.

Investigation on the structural properties in Er-doped PbTiO3 compounds: A correlation between experimental and theoretical results

“…This understanding aids the modification/optimization of the optical, structural and electrical properties of such materials [8][9][10][11][12]. Suwannasiri and Safari [13] reported that compact PbTiO 3 powders, doped with manganese and lanthanide elements [(Pb,Ln)(Ti,Mn)O 3 with Ln = La, Nd, Sm or Gd], synthesized by the conventional mixture of oxides and sintered at 1180-1250 • C for 3 h, presented densities over 95% of the theoretical density for all the additives studied.…”

Photoacoustic effect applied to sound speed measurement

“…This technique uses a mechanical wave generated on the surface of the material that travels at the speed of sound and is detected by using a piezoelectric transducer. The important advantages of this method are [4][5] that special sample preparation is not required and no signal amplification is required due to the high signal to noise ratio obtained with piezoelectric transducers.…”

“…In photoacoustic experiments the interaction between the laser beam and the lattice produces an acoustic signal PA(t) 5 which contains phenomenological information of the material. PA refers to the photoacoustic nature of the signal.…”

“…In our research laboratory, we have used this technique to characterize properties of diverse materials [3][4][5] .…”

Studies of the Substitution Yttrium in Pbtio3 Systems

“…In the case of these PT ceramics, disorder metal cations, at site B (Ti) of the perovskite structure ABO 3 (PbTiO 3 ), is the common point of all the complex compounds such as PZT 1 , PZN-PT 2 , PMN-PT 3 . However for compounds based on PbTiO 3 with good density and reducing the fragility and also to study the structural and dielectric properties, many dopants were used (Ca, Co, W, La, Sm, Dy and Mn…) [4][5][6][7][8][9] .…”