Multiferroic BaCoF₄ in Thin Film Form: Ferroelectricity, Magnetic Ordering, and Strain

Abstract

Multiferroic materials have simultaneous magnetic and ferroelectric long-range orders and can be potentially useful for a wide range of applications. Conventional ferroelectricity in oxide perovskites favors non-magnetic electronic configurations of transition metal ions, thus limiting the number of intrinsic multiferroic materials. On the other hand, this is not necessarily true for multiferroic fluorides. Using molecular beam epitaxy, we demonstrate for the first time that the multiferroic orthorhombic fluoride BaCoF 4 can be synthesized in thin film form. Ferroelectric hysteresis measurements and piezoresponse force microscopy show that the films are indeed ferroelectric.From structural information, magnetic measurements, and first principles calculations, a modified magnetic ground state is identified which can be represented as a combination of bulk collinear antiferromagnetism with two additional canted spin orders oriented along orthogonal axes of the BaCoF 4 unit cell. The calculations indicate that an anisotropic epitaxial strain is responsible for this unusual magnetic ground state.

BaMF4 (M = Mn, Co, Ni): New electrode materials for hybrid supercapacitor with layered polar structure

“…BaMF4 have been dispersedly studied as multiferroics for its coexistence of pyroelectricity and antiferromagnetism [22][23][24][25][26]. They are isostructural: the corner shared MF6 octahedra form the puckered sheets separated by Ba atoms, as shown in Fig.…”

Room temperature ferroelectricity in fluoroperovskite thin films

“…Besides the well-studied oxides, other materials with possible magneto-electric coupling are under investigations as well, as in the case of fluoride materials 11 – 15 . In particular, recent calculations predicted multiferroic signatures in the perovskite fluoride NaMnF 3 16 .…”

GdFe0.8Ni0.2O3: A Multiferroic Material for Low-Power Spintronic Devices with High Storage Capacity

“…Multiferroic devices have been attracting considerable attention because of their coexisting magnetism, , ferroelectricity, , and ferroelasticity. , They are also expected to feature prominently in the development of emerging data storage and processing devices due to the fact that the magnetic properties can be controlled by an electric field rather than an electric current. For example, there are recent reports of single-phase magneto-electric multiferroics with low damping for spintronic applications, magneto-elastic control of spintronic devices, and anisotropic control of magneto-dielectric coupling .…”