Stockholms universitet,Institutionen för material- och miljökemi (MMK),Chalmers University of Technology, Sweden; University of Warsaw, Poland,Stockholm Univ, Dept Mat & Environm Chem, S-10691 Stockholm, Sweden;Univ Warsaw, Fac Phys, Inst Expt Phys, Pasteura 5, PL-02093 Warsaw, Poland;Chalmers Univ Technol, Dept Chem & Chem Engn, SE-41296 Gothenburg, Sweden
We present a comprehensive study of the magnetic properties of Sr3-xYx(Fe1.25Ni0.75)O-7(-delta )(0 <= x <= 0.75). Experimentally, the magnetic properties are investigated using superconducting quantum interference device (SQUID) magnetometry and neutron powder diffraction (NPD). This is complemented by a theoretical study based on density functional theory as well as the Heisenberg exchange parameters. Experimental results show an increase in the Ned temperature (T-N) with an increase of Y concentrations and O occupancy. The NPD data reveal that all samples are antiferromagnetically ordered at low temperatures, which has been confirmed by our theoretical simulations for the selected samples. Our first-principles calculations suggest that the three-dimensional magnetic order is stabilized due to finite interlayer exchange couplings. The latter give rise to finite interlayer spin-spin correlations, which disappear above T-N.
Ämnesord
NATURVETENSKAP -- Kemi (hsv//swe)
NATURAL SCIENCES -- Chemical Sciences (hsv//eng)
TEKNIK OCH TEKNOLOGIER -- Materialteknik (hsv//swe)
ENGINEERING AND TECHNOLOGY -- Materials Engineering (hsv//eng)
NATURVETENSKAP -- Fysik -- Den kondenserade materiens fysik (hsv//swe)