Complex room-temperature ferrimagnetism induced by zigzag stripes of oxygen vacancies in Sr3YCo4O10+delta

authors	Khalyavin, DD; Chapon, LC; Suard, E; Parker, JE; Thompson, SP; Yaremchenko, AA; Kharton, VV
nationality	International
journal	PHYSICAL REVIEW B
keywords	LN; Y3+
abstract	The high-temperature ferromagnetism in Sr3YCo4O10+delta perovskite, whose origin has been the subject of considerable debate, has been studied by neutron powder diffraction and synchrotron x-ray diffraction measurements. Oxygen vacancy ordering creates a complex pattern of zigzag stripes in the oxygen-deficient CoO4+delta layers, where the Co ions are found in three distinct coordinations. The symmetry of this unprecedented structural modulation, in conjunction with the existence of different Co spin states, provides a straightforward explanation for the appearance of ferrimagnetism. A model for the magnetic structure compatible with these structural features is proposed, based on the refinement of powder neutron data. The macroscopic moment as a function of temperature that can be calculated from the values of the ordered spins extracted from refinements is in excellent agreement with bulk magnetization. Unlike previous models, a collinear G-type magnetic structure with uncompensated moments due to distinct spin states of Co imposed by different coordination is found.
publisher	AMER PHYSICAL SOC
issn	1098-0121
year published	2011
volume	83
issue	14
digital object identifier (doi)	10.1103/PhysRevB.83.140403
web of science category	Physics, Condensed Matter
subject category	Physics
unique article identifier	WOS:000289488300003