Multiferroic properties of pure and transition metal doped LaFeO3 nanoparticles

Abstract

The size, doping concentration, and magnetic field dependences of the magnetization M and the real part of the dielectric function 𝜀' in doped LaFe1−𝑥M𝑥O3 nanoparticles (NPs) are studied using a microscopic model. Although M increases, 𝜀′ decreases with decreasing NPs size in pure LaFeO3. Doping with different ions causes different strain which modifies the exchange interaction. As a consequence, M and 𝜀′ grow with increasing Mn or Zn ion doping, whereas both quantities decrease by doping with Ti or Al ions. The magneto-dielectric coefficient increases with an applied external magnetic field and Mn doping concentration in pure and Mn-doped LaFeO3 indicating that pure and doped LaFeO3 NPs exhibit a multiferroic behavior. A microscopic model is proposed to study multiferroic Bi2NiMnO6 thin films.