Perovskite-type oxides as susceptor materials in dielectric heating

Abstract

Dielectric properties of La 1-x Ce x MnO 3 perovskites are investigated in order to assess the heating behaviour in the wider context of the use of perovskite coatings in microwave assisted soot filter regeneration. Dielectric permittivities in the radio and microwave region for these perovskites were determined at room temperature. The dielectric constant and dielectric loss are related to ionic conduction at low frequencies, while at microwave frequencies storage and loss mainly proceed through reorientation of molecular dipoles. The dielectric constant rises for a higher degree of La substitution by Ce, which is explained by an increase of the number of cation/oxygen vacancies. Concurrently the mean perovskite crystallite size decreases, which is possibly related to defect formation. The dielectric constant declines for x ‡ 0.3, along with the formation of a separate, low dielectric permittivity CeO 2 phase. The La-Ce-Mn perovskites are further shown to exhibit a high thermal stability during repeated heating/cooling cycles.

Microwave Dielectric Properties of Scheelite Structured PbMoO4 Ceramic with Ultralow Sintering Temperature

“…To cofire with internal electrodes, such as Ag, Cu, Au, and Al, the dielectrics are required to possess lower sintering temperatures than the melting points of electrodes and also be chemically compatible with electrodes. In the past decades, hundreds of microwave dielectric materials have been reported, [6][7][8][9][10][11][12][13][14][15] but with high sintering temperatures. Hence, the decrease in sintering temperature is still a key problem in the application of low-temperature cofired ceramics (LTCC) technology.…”

Infrared emissivities and microwave absorption properties of perovskite Sm0.5Sr0.5Co1−xFexO3 (0≤x≤0.5)

“…Perovskite-type structure oxides (ABO 3 ) are widely used as cathode materials [12][13][14][15], gas sensors [16,17], new catalysts [18][19][20], for their high electrical conductivity, high dielectric constant, and high catalytic activity, which depend upon the different types and contents of metals occupying in the A and B sites [21][22][23]. Rare earth alkalide manganites show potentiality for thermochromic devices in the infrared range due to their charge * Corresponding author.…”