Exploiting Symmetry Mismatch to Control Magnetism in a Ferroelastic Heterostructure

被引：33

作者：

Guo, Er-Jia ^{[1
,2
,3
,4
]}

Desautels, Ryan ^{[1
]}

Lee, Dongkyu ^{[1
]}

Roldan, Manuel A. ^{[5
]}

Liao, Zhaoliang ^{[1
]}

Charlton, Timothy ^{[1
]}

Ambaye, Haile ^{[1
]}

Molaison, Jamie ^{[1
]}

Boehler, Reinhard ^{[1
,6
]}

Keavney, David ^{[7
]}

Herklotz, Andreas ^{[1
,8
]}

Ward, T. Zac ^{[1
]}

Lee, Ho Nyung ^{[1
]}

Fitzsimmons, Michael R. ^{[1
,9
]}

机构：

[1] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA

[2] Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China

[3] Chinese Acad Sci, Inst Phys, Beijing 100190, Peoples R China

[4] Univ Chinese Acad Sci, Ctr Mat Sci & Optoelect Engn, Beijing 100049, Peoples R China

[5] Arizona State Univ, Eyring Mat Ctr, Tempe, AZ 85287 USA

[6] Carnegie Inst Sci, Geophys Lab, Washington, DC 20005 USA

[7] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA

[8] Martin Luther Univ Halle Wittenberg, Inst Phys, D-06120 Halle, Saale, Germany

[9] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA

来源：

PHYSICAL REVIEW LETTERS | 2019年 / 122卷 / 18期

关键词：

SPIN-STATE TRANSITION; LACOO3;

D O I：

10.1103/PhysRevLett.122.187202

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

In the bulk, LaCoO3 (LCO) is a paramagnet, yet the low-temperature ferromagnetism (FM) is observed in tensile strained thin films, and its origin remains unresolved. Here, we quantitatively measured the distribution of atomic density and magnetization in LCO films by polarized neutron reflectometry (PNR) and found that the LCO layers near the heterointerfaces exhibit a reduced magnetization but an enhanced atomic density, whereas the film's interior (i.e., its film bulk) shows the opposite trend. We attribute the nonuniformity to the symmetry mismatch at the interface, which induces a structural distortion related to the ferroelasticity of LCO. This assertion is tested by systematic application of hydrostatic pressure during the PNR experiments. The magnetization can be controlled at a rate of -20.4% per GPa. These results provide unique insights into mechanisms driving FM in strained LCO films while offering a tantalizing observation that tunable deformation of the CoO6 octahedra in combination with the ferroelastic order parameter.

引用

页数：7

共 43 条

[1] EosFit7c and a Fortran module (library) for equation of state calculations [J].