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Complex-oxide materials exhibit a vast range of functional properties desirable for next-generation electronic, spintronic, magnetoelectric, neuromorphic, and energy conversion storage devices1-4. Their physical functionalities can be coupled by stacking layers of such materials to create heterostructures and can be further boosted by applying strain5-7. The predominant method for heterogeneous integration and application of strain has been through heteroepitaxy, which drastically limits the possible material combinations and the ability to integrate complex oxides with mature semiconductor technologies. Moreover, key physical properties of complex-oxide thin films, such as piezoelectricity and magnetostriction, are severely reduced by the substrate clamping effect. Here we demonstrate a universal mechanical exfoliation method of producing freestanding single-crystalline membranes made from a wide range of complex-oxide materials including perovskite, spinel and garnet crystal structures with varying crystallographic orientations. In addition, we create artificial heterostructures and hybridize their physical properties by directly stacking such freestanding membranes with different crystal structures and orientations, which is not possible using conventional methods. Our results establish a platform for stacking and coupling three-dimensional structures, akin to two-dimensional material-based heterostructures, for enhancing device functionalities8,9.

Nonmagnetic heavy metals can develop a magnetic moment due to the proximity of a magnetic layer. Here, the sign of the proximity effect in Pt and W grown on the ferrimagnetic insulator Dy${}_{3}$Fe${}_{5}$O${}_{12}$ (DyIG) is examined. Polarized neutron reflectometry indicates the importance of a clean metal/garnet interface, and shows that the proximity effect in Pt/DyIG is positive above and below the DyIG compensation temperature, indicating a different origin compared to that of Pt adjacent to a ferrimagnetic metal alloy.

Growth, structural, magnetic, and spin transport properties of epitaxial scandium-substituted terbium iron garnet (TbScIG) thin films on gadolinium gallium garnet [GGG, (111) orientation] substrates are reported as a function of Sc content. The films are epitaxial on GGG without strain relaxation up to a thickness of 90 nm and exhibit perpendicular magnetic anisotropy. Sc, a nonmagnetic cation, occupies up to 40% of the octahedral Fe sites. Increasing Sc lowers the compensation temperature and Curie temperature and increases the room-temperature saturation magnetization from 37 kA/m for ${\mathrm{Tb}}_{2.8}{\mathrm{Fe}}_{5.2}{\mathrm{O}}_{12}$ to 59 kA/m for ${\mathrm{Tb}}_{2.8}{\mathrm{Sc}}_{0.8}{\mathrm{Fe}}_{4.4}{\mathrm{O}}_{12}$. Anomalous Hall effect-like spin Hall magnetoresistance measurements were performed to determine the effect of scandium content on spin mixing conductance of the TbScIG|Pt interface. The spin mixing conductance increased significantly with an increase in Sc content, consistent with a dependence of spin transport on the net Fe magnetization instead of the total magnetization of the garnet.

Nanometer-thin rare-earth iron garnet films with perpendicular magnetic anisotropy are among the most promising materials for fast and low-energy spintronics applications. Here, the authors demonstrate ultrafast control of intrinsically stabilized submicrometer bubble domains in these materials. By employing powerful x-ray imaging techniques both in transmission and with surface sensitivity, and by combining this with nanosecond electrical pulses and femtosecond laser excitation, they deterministically create, and image, these bubble states $i\phantom{\rule{0}{0ex}}n$ $s\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u$. The topology, the chirality, and the switching phase diagram of these twisted spin structures are all resolved by direct imaging.

We demonstrate a conceptually new mechanism to generate an in-plane spin current with out-of-plane polarization in a nonmagnetic metal, detected by nonlocal thermoelectric voltage measurement. We generate out-of-plane (∇T_{OP}) and in-plane (∇T_{IP}) temperature gradients, simultaneously, acting on a magnetic insulator-Pt bilayer. When the magnetization has a component oriented perpendicular to the plane, ∇T_{OP} drives a spin current into Pt with out-of-plane polarization due to the spin Seebeck effect. ∇T_{IP} then drags the resulting spin-polarized electrons in Pt parallel to the plane against the gradient direction. This finally produces an inverse spin Hall effect voltage in Pt, transverse to ∇T_{IP} and proportional to the out-of-plane component of the magnetization. This simple method enables the detection of the perpendicular magnetization component in a magnetic insulator in a nonlocal geometry.

Triplet ground-state organic molecules are interesting with respect to several emerging technologies but typically exhibit limited stability. We report two organic diradicals, one of which possesses a triplet ground state (2J/kB = 234 ± 36 K) and robust stability at elevated temperatures. We are able to sublime this high-spin diradical under high vacuum at 140 °C with no significant decomposition.

Polycrystalline single-phase europium iron garnet films (EuIG, Eu3Fe5O12, a ferrimagnetic insulator), with thicknesses from 25 to 50 nm and roughness