Addressing the Electrical Transport Behavior of Rare Earth Doped Multiferroic Bismuth Ferrite

Abstract

Frequently observed deformation of P‐E hysteresis loops of multiferroic BiFeO3 (BFO) and doped BFO by leakage currents hindered potential applications of BFO. Apart from the increased power consumption and heating due to leakage current, charge injection associated with the electrical transport properties (I‐V) is also believed to be involved in accelerating fatigue as well as raising other reliability issues for real applications. Suitable thin film structure with selection of proper contacts as well as incorporating dopants in BFO, promising results were observed which significantly suppress the leakage current. However, bulk BFO specimen possesses appreciable difficulties for I‐V measurements. In this paper, we have carried out electrical transport measurements on sub‐millimeter thick bulk BFO and rare earth doped BFO applying different electrical contacts under high voltage biasing configuration. Gd and Ho doped BFO specimens were measured which were processed by slow step sintering schedule. Our experimental findings revealed that Gd & Ho doping in Fe deficient BFO promotes the suppression of oxygen vacancies and in turn reduce leakage current which support the P‐E loop. Attempt has been made to explain above results by common transport models which includes Schottky, space charge limited conduction and Poole‐Frenkel effect.