Artificially controlled magnetic domain structures in ferromagnetic dots∕ferroelectric heterostructures

Abstract

A variation in the magnetization and magnetic domain structures of epitaxial Fe dots on a single crystal BaTiO 3 substrate is demonstrated in association with the structural phase transition of ferroelectric BaTiO 3. The temperature dependent magnetization of Fe dots drops suddenly at 282 K and increases again at 189 K with decreasing temperature. The variations clearly correspond to the successive structural phase transitions of BaTiO 3 from tetragonal to orthorhombic phases and from orthorhombic to rhombohedral phases. After a thermal cycle between room temperature and 150 K passing through these phase transitions, the initial magnetic domain structure of Fe dots with an enclosed magnetic flux structure changes to a single-domain-like structure due to interfacial strain between Fe and BaTiO 3 arising from possible switching of c-axis orientation of BaTiO 3 substrate.

Giant magnetoelastic effects in BaTiO3-based extrinsic multiferroic hybrids

“…22 They reported large changes of the magnetization and the electric resistivity in La 0.7 Sr 0.3 MnO 3 /BaTiO 3 (LSMO/BTO) extrinsic multiferroic hybrids, whenever BTO undergoes a structural phase transition. In recent years, further experiments using LSMO/BTO, 7,23 Fe/BTO, [24][25][26] In these experiments, magnetization jumps were observed caused by strain changes of the respective ferromagnetic thin film, which are induced by the structural phase transitions of BTO. However, the experimental results could hardly be explained in a quantitative manner, since ferroelectric BTO forms a multi-domain state upon crossing the phase transitions without any external field applied to the crystal.…”

Magnetoelectric coupling in a ferroelectric/ferromagnetic chain revealed by ferromagnetic resonance

“…To be specific, we focus on a special class of ME coupled materials, so-called composite MFs [6,19], that may be synthesized from a wide range of materials that, when composed together yield a strong ME coupling and stable ferroelectric (FE) and ferromagnetic (FM) orders at room temperatures. An example that has been studied intensively, theoretically and experimentally is BaTiO 3 (BTO)/Fe [20][21][22][23][24][25][26][27][28][29][30]. The ME coupling in this system is predicted to be an interfacial effect and relatively high [21,28,31,32].…”

Ultrafast transient dynamics in composite multiferroics

“…In addition to the fundamental questions regarding the origin of the underlying physics, this observation holds the promise of qualitatively new device concepts. MF memory devices [13] with multi-state data storage and heterogeneous read/write capability through the interfacial strain effects [14][15][16][17][18], the direct electric field effects [19][20][21][22][23][24][25][26][27], and exchange-bias [28][29][30] are a few examples. A key element thereby is the strength and symmetry of MF coupling and whether it is utilizable for swiftly transferring/ converting FM into FE information.…”