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In-plane ferroelectric polarization in BaTiO3 (BTO) epitaxial thin films on MgAl2O4(001) (MAO) is reported. The directional dependence of both in-plane polarization curves and Raman spectroscopy shows that the films have an orthorhombic structure at room temperature, in contrast to the tetragonal structure of the corresponding bulk. The largest in-plane polarization value among BTO-based tensile-strained films is obtained. The temperature dependence of the lattice constants shows that the Curie temperature of the thin films is as high as 220 °C, which is higher than that of the bulk by 100 °C. The significant enhancement of the Curie temperature is attributed to high-quality coherent epitaxial growth due to perfect matching between the lattice parameter of the c-axis of BTO and that of MAO. [ABSTRACT FROM AUTHOR]

We report on B2-ordering dependence of magnetostatic surface spin waves in ferromagnetic FeRh at room temperature. Spin waves transmit over a distance longer than 21 μm in highly ordered FeRh alloys even with relatively large spin-orbit interaction. The long-range transmission likely arises from the induced Rh moments of the ordered FeRh due to ferromagnetic exchange interaction between Fe and Rh. The results indicate a potential of using FeRh in spintronic and magnonic applications by integrating with other fascinating magnetic characteristics of FeRh such as electric field induced magnetic phase transition. [ABSTRACT FROM AUTHOR]

B2-ordered FeRh has been known to exhibit antiferromagnetic-ferromagnetic (AF-F) phase transitions in the vicinity of room temperature. Manipulation of the Néel order via AF-F phase transition and recent experimental observation of the anisotropic magnetoresistance in antiferromagnetic FeRh has proven that FeRh is a promising candidate for antiferromagnetic memory material. In this work, we demonstrate sequential write and read operations in antiferromagnetic memory resistors made of B2-orderd FeRh thin films by a magnetic field and electric current only, which open a realistic pathway towards operational antiferromagnetic memory devices. [ABSTRACT FROM AUTHOR]

We report the studies of tuning the exchange bias at ferromagnetic Fe/metamagnetic FeRh bilayer interfaces. Fe/FeRh(111) bilayers show exchange bias in the antiferromagnetic state of FeRh while no exchange bias occurs at Fe/FeRh(001) interface. The contrasting results are attributed to the spin configurations of FeRh at the interface, i.e., the uncompensated ferromagnetic spin configuration of FeRh appears exclusively for (111) orientation. The exchange bias disappears as the bilayers are warmed above the antiferromagnetic-ferromagnetic transition temperature. The direction of the exchange bias for Fe/FeRh(111) is also found to be perpendicular to the coolingfield direction, in contrast to the commonly observed direction of exchange bias for ferromagnetic/antiferromagnetic interfaces. In view of these results, the exchange bias in Fe/FeRh bilayers with the (111) crystallographic orientation should be useful for the design of rapid writing technology for magnetic information devices. [ABSTRACT FROM AUTHOR]