Effect of oxygen vacancies and cationic valence state on multiferroicity and magnetodielectric coupling in (1-x)BaTiO3.(x)LaFeO3 solid solution
P. Maneesha, Koyal Suman Samantaray, Suresh Chandra Baral, Grace Brzykcy, Indranil Bhaumik, A. Mekki, Arjun K. Pathak, Somaditya Sen
Abstract
A solid solution of (1-x)BaTiO 3 –(x)LaFeO 3 (x = 0, 0.007, 0.015, 0.031, 0.062) has been investigated for room temperature multiferroicity and magnetodielectric effect. The incorporation of La and Fe ions in ferroelectric BaTiO 3 leads to increased lattice disorder and generation of oxygen vacancies that induces magnetism . A detailed correlated study using XRD , XPS and Raman spectroscopy is being reported. A typical ferromagnetic and ferroelectric nature of each sample are confirmed by M−H and P–E hysteresis loops, respectively at room temperature. Temperature dependent dielectric studies reveal the decrease of transition temperature from 137 0 C for undoped to room temperature for increasing substitution. The changes in the dielectric property with applied magnetic field shows the indications of magnetodielectric effect. For x = 0.015, existence of both proper ferroelectric without lossy properties and ferromagnetic properties in a single tetragonal phase makes it a perfect room temperature multiferroic material . For this sample, the magnetodielectric coupling is the strongest with Magnetocapacitance of ∼2.7% and Magneto loss of ∼0.8% at 10 kHz and 1 T. The multiferroicity and the magnetodielectric effect exhibited by this material has been correlated to the structural properties, electric and magnetic properties , changes in valence states, and oxygen vacancy ( Ov ).