Magnetic switch of polarization in epitaxial orthorhombic YMnO3 thin films

Abstract

We report on the growth and characterization of epitaxial thin films of orthorhombic YMnO3. It is found that a ferroelectric polarization exists along c-axis (Pc∼90 nC/cm2) and a magnetic field induces the development of a ferroelectric polarization along a-axis (Pa) while suppressing Pc. This field-induced switching is consistent with the existence of a cycloidal magnetic order in YMnO3. This finding evidences that a noncollinear spin arrangement in thin films allows switchable electrical polarization and of tunability of their dielectric response by magnetic field.

Continuously tunable magnetic phase transitions in the DyMn1−xFexO3 system

“…7,13 Our experiment shows that the AFM transition temperatures of DyMn 1Àx Fe x O 3 are modified by Fe doping, which stems from subtle structural change. For DyMnO 3 and low Fe doping samples with x 0.2, a relation b > a > c/ ffiffi ffi 2 p is found, suggesting a static Jahn-Teller orbital ordering. Therefore, for x 0.5, the Fe doping can affect the magnetic exchange interaction in the following way: because e g orbital of Fe 3þ ion is half occupied and that of Mn 3þ ion is quarter occupied, such an occupied electronic state enhances the AFM exchange interaction of the whole system, both in-plane and interplane, according to the Hund rule.…”

“…For LaMnO 3 , there is an A-type antiferromagnetic order due to the dominating FM interaction of e g in-plane. 20 Here, DyMnO 3 shows an incommensurate antiferromagnetic configuration with a wave number of 0.72 at T N .…”

“…1,2 A great amount of work has been done to explore mutual control of the electric and magnetic degrees of freedoms, the so-called magnetoelectric (ME) coupling. [3][4][5] Meanwhile, the abundant phase transitions that occur in some multiferroic systems have inspired great interest. 6,7 The dielectric property changes around the magnetic phase transition can offer a way to achieve magnetodielectric coupling.…”

Dielectric relaxation in the DyMn1−xFexO3 system

“…[3][4][5][6] A great amount of work has been done to explore mutual control of these two degrees of freedoms, the so-called magnetoelectric (ME) coupling. [7][8][9] On the other hand, the dielectric property changes around the magnetic phase transition can offer a way to achieve magnetodielectric coupling, [10][11][12][13] which also provides an alternative way to achieve more operation of degrees of freedoms. Magnetic field induced dielectric constant changes are observed in metastable orthorhombic HoMnO 3 and YMnO 3 below their incommensurate antiferromagnetic (AFM) transition temperature of 42 K. 14 To achieve real applications based on spin related dielectric properties, it seems to be necessary to study their frequency and temperature dependence.…”

Structural transformation and charge transfer induced ferroelectricity and magnetism in annealed YMnO3

“…25,26 However, orthorhombic YMnO 3 growth as an epitaxial thin film due to a surface strain effect has also been confirmed. [27][28][29] The orthorhombic YMnO 3 phase found herein could be attributed to a strong surface strain, which is commonly present in nano-particle systems. 30,31 Also, for the hexagonal phase, the a-axis lattice parameter decreases and the c-axis lattice parameter expands with increasing T a , which could be caused by the decrease in surface strain as the grain size increases.…”