Magnetic exchange interactions in B-, Si-, and As-doped Fe2P from first-principles theory
2012 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 85, no 22, 224435- p.Article in journal (Refereed) Published
Di-iron phosphide (Fe2P) is a parent system for a set of magnetocaloric materials. Although the magnetic ordering temperature (T-C = 215 K) of the stoichiometric composition is too low for room-temperature magnetic refrigeration, the partial replacement of P with B, Si, or As elements results in a steep increase in the magnetic ordering temperature. Doping leads to different equilibrium volumes and hexagonal axial ratios (c/a) within the same crystallographic phase over a wide concentration range. Here, using first principles theory, we decompose the change in the total magnetic exchange interaction upon doping into chemical and structural contributions, the latter including the c/a-ratio and volume effects. We demonstrate that for the investigated alloys the structural effect can be ascribed mainly to the decrease in the c/a ratio that strengthens the magnetic exchange interactions between the two Fe sublattices.
Place, publisher, year, edition, pages
2012. Vol. 85, no 22, 224435- p.
COHERENT-POTENTIAL APPROXIMATION; ROOM-TEMPERATURE; CRYSTAL-STRUCTURE; SUBSTITUTED FE2P; SINGLE-CRYSTAL; TRANSITION; ALLOYS; REFRIGERATION; BEHAVIOR; SYSTEM
IdentifiersURN: urn:nbn:se:kth:diva-99229DOI: 10.1103/PhysRevB.85.224435ISI: 000305783500003ScopusID: 2-s2.0-84863308867OAI: oai:DiVA.org:kth-99229DiVA: diva2:541913
FunderSwedish e‐Science Research Center
QC 201207262012-07-262012-07-232013-04-08Bibliographically approved