Emergent nanoscale superparamagnetism at oxide interfaces

Autor: Ariando, Thirumalai Venkatesan, Eli Zeldov, J. Cuppens, Martin E. Huber, M. L. Rappaport, Sumilan Banerjee, K. Michaeli, Y. Myasoedov, Yonathan Anahory, Changjian Li, H. R. Naren, Anton Yakovenko, Lior Embon, Alexander Y. Meltzer
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Nature Communications, Vol 7, Iss 1, Pp 1-9 (2016)
Nature Communications
Popis: Atomically sharp oxide heterostructures exhibit a range of novel physical phenomena that are absent in the parent compounds. A prominent example is the appearance of highly conducting and superconducting states at the interface between LaAlO3 and SrTiO3. Here we report an emergent phenomenon at the LaMnO3/SrTiO3 interface where an antiferromagnetic Mott insulator abruptly transforms into a nanoscale inhomogeneous magnetic state. Upon increasing the thickness of LaMnO3, our scanning nanoSQUID-on-tip microscopy shows spontaneous formation of isolated magnetic nanoislands, which display thermally activated moment reversals in response to an in-plane magnetic field. The observed superparamagnetic state manifests the emergence of thermodynamic electronic phase separation in which metallic ferromagnetic islands nucleate in an insulating antiferromagnetic matrix. We derive a model that captures the sharp onset and the thickness dependence of the magnetization. Our model suggests that a nearby superparamagnetic–ferromagnetic transition can be gate tuned, holding potential for applications in magnetic storage and spintronics.
Interfaces between complex oxides can exhibit diverse emergent phenomena, such as magnetic and superconducting order. Here, the authors evidence the emergence of nanoislands with a thickness dependent transition from superparamagnetic to ferromagnetic behaviour at LaMnO3/SrTiO3 thin film interfaces.
Databáze: OpenAIRE