Multiferroic clusters: a new perspective for relaxor-type room-temperature multiferroics

TL;DR

This paper introduces multiferroic clusters in relaxor ferroelectric single-phase materials, demonstrating room-temperature multiferroicity with strong magnetoelectric coupling, promising for sensor and memory applications.

Contribution

It presents a novel perspective on relaxor multiferroics by identifying multiferroic clusters that exhibit strong magnetoelectric effects at room temperature.

Findings

Emergence of multiferroic clusters from ferrimagnetic regions

Large magnetoelectric coupling coefficients measured at room temperature

Polar nanoregions transform into static-PNR enabling multiferroic behavior

Abstract

Multiferroics are promising for sensor and memory applications, but despite all efforts invested in their research no single-phase material displaying both ferroelectricity and large magnetization at room-temperature has hitherto been reported. This situation has substantially been improved in the novel relaxor ferroelectric single-phase , where polar nanoregions (PNR) transform into static-PNR (SPNR) as evidenced by piezoresponse force microscopy (PFM) and simultaneously enable congruent multiferroic clusters (MFC) to emerge from inherent ferrimagnetic Bi(Fe,Co)O3 regions as verified by magnetic force microscopy (MFM) and secondary ion mass spectrometry (SIMS). On these MFC, exceptionally large direct and converse magnetoelectric coupling coefficients, at room-temperature, were measured by PFM and MFM respectively. We expect the non-ergodic relaxor properties which are governed by the Bi0.5K0.5TiO3 component to play a vital role in the strong ME coupling, by providing an electrically and mechanically flexible environment to MFC. This new class of non-ergodic relaxor multiferroics bears great potential for applications. Especially the prospect of a ME nanodot storage device seems appealing.