Dielectric relaxation in epitaxial films of paraelectric-magnetic SrTiO3-SrMnO3 solid solution

Abstract

Magneto-dielectric properties of (A2+)MnO3-type perovskites are attractive for applications and stimulate extensive studies of these materials. Here, the complex dielectric and magnetic responses are investigated as in epitaxial films of SrTi0.6Mn0.4O3, solid solution of paraelectric SrTiO3 and magnetic SrMnO3. The impedance and resonance measurements at frequencies of 10−2–1010 Hz and temperatures of 10–500 K reveal broad dielectric anomalies centered at 100–200 K, while the films are paramagnetic at all temperatures. Analysis shows polaronic electrical conductivity behind the observed behavior. Electron-phonon correlations, rather than spin-phonon correlations, are suggested to produce the apparent magneto-dielectric responses in many multiferroic manganites.

Dielectric Spectroscopy of Non-Stoichiometric SrMnO3 Thin Films

“…The ln (fr)−1000/T curves corresponding to non-stoichiometric SMO films were extracted in the frequency-dielectric spectrum, and a linear fitting was performed. The activation energy of the Sr-rich SMO film was ~0.12 eV, while that of the Mn-rich SMO film was ~0.14 eV (Figure 6), which closely resembles the relaxation activation energy associated with the Jahn-Teller (JT) polaron hopping related to Mn 3+ ions in manganese oxide systems, as has been reported [51][52][53]. The JT polaron in manganese In addition, the dielectric relaxation induced by the movement of ferroelectric domain walls often occurs at high frequencies (above MHz), and also should be removed from the list of possible causes of the present relaxation mechanism.…”

Effect of Graphene Encapsulated Styrene-butyl Acrylate Copolymer Microspheres on Enhancing the Dielectric Properties of Polymethyl Methacrylate

“…With the development of electronic technology, the demand for dielectric materials is pressing and the ultimate performance requirements are high [1][2][3] . Dielectric composites range from dielectric-dielectric composites to dielectric-conductive composites and then composite llers are added to the composites to improve the dielectric constant of the composites and control the dielectric loss and percolation threshold of the composites [4][5][6][7] .The so-called dielectric-dielectric composite material is to add ceramic llers to the composite material. However, the dielectric-dielectric composites usually need to be lled with high content of ceramic llers in order to improve the dielectric properties of the composites [8][9][10][11] .…”