Magnetic and dielectric properties of Fe3BO6 nanoplates prepared through self-combustion method

Abstract

In the present investigation, a facile synthesis method is explored involving a self-combustion of a solid precursor mixture of iron oxide Fe<inf>2</inf>O<inf>3</inf> and boric acid (H<inf>3</inf>BO<inf>3</inf>) using camphor (C<inf>10</inf>H<inf>16</inf>O) as fuel in ambient air in order to form a single phase Fe<inf>3</inf>BO<inf>6</inf> crystallites. X-ray diffraction (XRD), Field emission electron microscopy (FESEM), magnetic, and dielectric properties of as prepared sample are studied. From XRD pattern, a single phase compound is observed with an orthorhombic crystal structure (Pnma space group), with average crystallite size of 42 nm. A reasonably uniform size distribution of the plates and self-assemblies is retained in the sample. A magnetic transition is observed in dielectric permittivity (at ~445 K) and power loss (at ~435 K) when plotted against temperature. Aweak peak occurs near 330K due to the charge reordering in the sample. For temperatures above the transition temperature, a sharp increase of the dielectric loss is observed which occurs due to the presence of thermally activated charge carriers. A canted antiferromagnetic Fe3+ ordering in a Fe<inf>3</inf>BO<inf>6</inf> lattice with a localized charge surface layer is an apparent source of exhibiting a ferroelectric feature in this unique example of a centrosymmetric compound. An induced spin current over the Fe sites thus could give rise to a polarization hysteresis loop. Due to the presence of both ferromagnetic as well as polarization ordering, Fe<inf>3</inf>BO<inf>6</inf> behaves like a single phase multiferroic ceramics. © The Author(s).