Particulate composites of Li0.5Co0.75Fe2O4 and BaTiO3 with mixed structure have been synthesized by the normal ceramic method with a variation of the molar percentages. X-ray diffraction was used to carry out the structural analysis and confirm the presence of constituent phases in the composites. The dc resistivity was measured as a function of temperature and molar percentage of constituent phases. The relative dielectric constant with variation of frequency (in the range 20 Hz to 1 MHz) and temperature at four fixed frequencies (i.e. 1 kHz, 10 kHz, 100 kHz and 1 MHz) was studied. The ac conductivity was calculated from dielectric data to understand the conduction mechanism. Hysteresis measurements were carried out to determine the saturation magnetization. The variation in magnetic behaviour with the composition of constituent phases was measured as a function of the applied dc magnetic field. A maximum magnetoelectric voltage coefficient of about 372 µV cm−1 Oe−1 was observed for the (0.3)Li0.5Co0.75Fe2O4/(0.7)BaTiO3 composite. The ME conversion factor has been explained in terms of molar constitution of ferrite–ferroelectric phases and resistivity.

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The paper reports the synthesis of Ba 1-x Sr x TiO 3 (BST) for x = 0.20, 0.25, and 0.30 via hydroxide co-precipitation route to result into the BST nanoparticles of size nearly 50 nm. The La 0.67 Sr 0.33 MnO 3 (LSMO) is also synthesized using co-precipitation route to achieve nanocrystaline particles. Further, the magnetodielectric (MD) composites of BST0.20, BST0.25, and BST0.30 are formed by addition of the LSMO at y = 0.1 and 0.2. The parent BST compositions are analysed for its dielectric properties. The composite LSMO-BST (LBST) is investigated for the variation of dielectric constant and impedance spectra as a function of applied magnetic field for the frequency between 500 Hz to 1 MHz. The observations on MD effect show that the dielectric constant possesses contributions due to magnetic field dependant interfacial polarization and variations due to the induced stress.

To understand possible interaction between magnetic and electric order parameters of Fe-doped Sr x Ba 1Àx Nb 2 O 6 (SBN), Fe-doped Sr 0:5 Ba 0:5 Nb 2 O 6 (SBN50) and Sr 0:4 Ba 0:6 Nb 2 O 6 (SBN40) are synthesized and investigated. Synthesis has been carried out via ceramic route. The paper reports synthesis, crystal structure, dielectric properties, P-E hysteresis loops, M-H hysteresis loops and magneto-capacitance of the Fe-doped SBN compositions. All the compositions are observed to exhibit a useful value of magnetocapacitance, especially at frequencies less than 10 kHz.