Solid phases of spatially nanoconfined oxygen: a neutron scattering study.
We present a comprehensive neutron scattering study on solid oxygen spatially confined in 12 nm wide alumina nanochannels. Elastic scattering experiments reveal a structural phase sequence known from bulk oxygen. With decreasing temperature cubic γ-, orthorhombic β- and monoclinic α-phases are unambiguously identified in confinement. Weak antiferromagnetic ordering is observed in the confined monoclinic α-phase. Rocking scans reveal that oxygen nanocrystals inside the tubular channels do not form an isotropic powder. Rather, they exhibit preferred orientations depending on thermal history and the very mechanisms, which guide the structural transitions.
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany.
Danny
D
Kojda
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany.
Dirk
D
Wallacher
Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France.
Simon
S
Baudoin
Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France.
Thomas
T
Hansen
Technische Universität Hamburg-Harburg, 21073 Hamburg, Germany.
Patrick
P
Huber
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 14109 Berlin, Germany.
Tommy
T
Hofmann