title: Tuneable Magnetic Phase Transitions in Layered CeMn2Ge(2-x)Six Compounds.
abstract: The structural and magnetic properties of seven CeMn2Ge(2-x)Six compounds with x = 0.0-2.0 have been investigated in detail. Substitution of Ge with Si leads to a monotonic decrease of both a and c along with concomitant contraction of the unit cell volume and significant modifications of the magnetic states - a crossover from ferromagnetism at room temperature for Ge-rich compounds to antiferromagnetism for Si-rich compounds. The magnetic phase diagram has been constructed over the full range of CeMn2Ge(2-x)Six compositions and co-existence of ferromagnetism and antiferromagnetism has been observed in CeMn2Ge1.2Si0.8, CeMn2Ge1.0Si1.0 and CeMn2Ge0.8Si1.2 with novel insight provided by high resolution neutron and X-ray synchrotron radiation studies. CeMn2Ge(2-x)Six compounds (x = 0, 0.4 and 0.8) exhibit moderate isothermal magnetic entropy accompanied with a second-order phase transition around room temperature. Analysis of critical behaviour in the vicinity of TC(inter) for CeMn2Ge2 compound indicates behaviour consistent with three-dimensional Heisenberg model predictions.
authors.affiliation: 1] Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia [2] Department of Electrical &Electronic Engineering, Faculty of Engineering, National Defence University of Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur, Malaysia.
authors.forename: M F
authors.initials: MF
authors.lastname: Md Din
authors.affiliation: 1] Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia [2] Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, NSW 2234, Australia.
authors.forename: J L
authors.initials: JL
authors.lastname: Wang
authors.affiliation: Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Z X
authors.initials: ZX
authors.lastname: Cheng
authors.affiliation: Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: S X
authors.initials: SX
authors.lastname: Dou
authors.affiliation: Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, NSW 2234, Australia.
authors.forename: S J
authors.initials: SJ
authors.lastname: Kennedy
authors.affiliation: Bragg Institute, Australian Nuclear Science and Technology Organization, Lucas Heights, NSW 2234, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Avdeev
authors.affiliation: School of Physical, Environmental and Mathematical Sciences, The University of New South Wales, Canberra, ACT 2600, Australia.
authors.forename: S J
authors.initials: SJ
authors.lastname: Campbell