Resonant soft x-ray scattering from La(1-x)Sr(x)MnO(3) quantum wire arrays

TL;DR

This paper demonstrates the use of resonant soft x-ray scattering to analyze magnetic superstructures in patterned La(1-x)Sr(x)MnO(3) quantum wire arrays, revealing a commensurate antiferromagnetic order and introducing a simple scattering model.

Contribution

It presents a novel application of RSXS to patterned oxide wires and introduces an analytic model for interpreting magnetic superstructures.

Findings

Detection of magnetic superstructure with period of five wires

Evidence of commensurate antiferromagnetism in the wires

Development of a semi-quantitative scattering model

Abstract

We describe a strategy for using resonant soft x-ray scattering (RSXS) to study the electronic structure of transition metal oxide quantum wires. Using electron beam lithography and ion milling, we have produced periodic, patterned arrays of colossal magnetoresistance (CMR) phase La(1-x)Sr(x)MnO(3) consisting of ~ 5000 wires, each of which is 80 nm in width. The scattered intensity exhibits a series of peaks that can be interpreted as Bragg reflections from the periodic structure or, equivalently, diffraction orders from the grating-like structure. RSXS measurements at the Mn L(2,3) edge, which has a large magnetic cross section, show clear evidence for a magnetic superstructure with a commensurate period of five wires, which we interpret as commensurately modulated antiferromagnetism. This superstructure, which is accompanied by non-trivial reorganization of the magnetization within each wire, likely results from classical dipole interactions among the wires. We introduce a simple, exactly soluble, analytic model of the scattering that captures, semi-quantitatively, the primary features in the RSXS data; this model will act as a foundation for forthcoming, detailed studies of the magnetic structure in these systems.