https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Diagenetic formation of greigite and pyrrhotite in gas hydrate marine sedimentary systems https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3504 Sat 24 Mar 2018 07:20:36 AEDT ]]> Group-theoretical analysis of structural instability, vacancy ordering and magnetic transitions in the system troilite (FeS)–pyrrhotite (Fe1−xS) https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38136 0.875S. It is concluded that the Besnus transition is a magnetically driven transition characterized by the rotation of the moments out of the crystallographic plane to which they are confined above the transition, accompanied by small atomic displacements that lower the symmetry from monoclinic to triclinic at low temperatures. Based on the phase diagram, magnetically driven phase transitions at low temperatures are predicted in all the commensurate superstructures of pyrrhotite. Based on the phase diagram, magnetically driven spin reorientations at low temperatures are predicted in all the commensurate superstructures of pyrrhotite. The exact nature of the spin rotation is determined by the symmetry of the vacancy-ordered state and based on this spin-flop transitions in 3C and 5C pyrrhotite and a continuous rotation akin to that seen in 4C pyrrhotite are predicted. A Besnus-type transition is also possible in 6C pyrrhotite. Furthermore, it is clarified that 3C and 4C pyrrhotite carry a ferrimagnetic moment whereas 5C and 6C are antiferromagnetic.]]> Fri 06 Aug 2021 16:13:40 AEST ]]>