Abstract
Noncollinear magnetism can play an important role in multiferroic materials but is relatively understudied in oxide heterostructures compared to their bulk counterparts. Using variable temperature magnetometry and neutron diffraction, we demonstrate the presence of helical magnetic ordering in CaMn7O12 and Ca1-xSrxMn7O12 (for x up to 0.51) thin films. Consistent with bulk Ca1-xSrxMn7O12, the net magnetization increases with Sr doping. Neutron diffraction confirms that the helical magnetic structure remains incommensurate at all values of x, while the fundamental magnetic wavevector increases upon Sr substitution. This result demonstrates a chemical-based approach for tuning helical magnetism in quadruple perovskite films and enables future studies of strain and interfacial effects on helimagnetism in oxide heterostructures.
| Original language | English |
|---|---|
| Article number | 224419 |
| Journal | Physical Review B |
| Volume | 98 |
| Issue number | 22 |
| DOIs | |
| State | Published - Dec 19 2018 |
Funding
A.H. was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Workforce Development for Teachers and Scientists, Office of Science Graduate Student Research (SCGSR) program. The SCGSR program is administered by the Oak Ridge Institute for Science and Education for the DOE under Contract No. DE-SC0014664. S.J.M. was supported by the Army Research Office (W911NF-15-1-0133); A.H. also acknowledges partial support from W911NF-15-1-0133. R.D.J. acknowledges support from a Royal Society Research Fellowship. The authors thank W. Chen, R. Erwin, L. Harriger, Md. T. Hassan, S. Watson, Z. Xu, and Y. Zhao for supporting the and neutron diffraction measurements at the NCNR. The work at Oak Ridge National Laboratory (ORNL) was supported by U.S. DOE, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division (XRD and SQUID characterizations). This work also used resources of Spallation Neutron Source and High Flux Isotope Reactor, which are DOE Office of Science User Facilities. The authors acknowledge the Science and Technology Facility Council (STFC, UK) for the provision of neutron beam time on the WISH instrument.
| Funders | Funder number |
|---|---|
| Office of Science Graduate Student Research | |
| SCGSR | |
| U.S. Department of Energy | |
| Army Research Office | W911NF-15-1-0133 |
| Office of Science | |
| Basic Energy Sciences | |
| Workforce Development for Teachers and Scientists | |
| Oak Ridge National Laboratory | |
| Oak Ridge Institute for Science and Education | DE-SC0014664 |
| Division of Materials Sciences and Engineering | |
| Royal Society |