%0 Journal Article
%A Sanjeewa, Liurukara
D.
%A Garlea, V. Ovidiu
%A McGuire, Michael A.
%A McMillen, Colin D.
%A Kolis, Joseph W.
%D 2019
%T Magnetic Ground State Crossover in a Series of Glaserite
Systems with Triangular Magnetic Lattices
%U https://acs.figshare.com/articles/journal_contribution/Magnetic_Ground_State_Crossover_in_a_Series_of_Glaserite_Systems_with_Triangular_Magnetic_Lattices/7691903
%R 10.1021/acs.inorgchem.8b03418.s001
%2 https://acs.figshare.com/ndownloader/files/14303204
%K heat capacity anomaly
%K VO 4
%K FM
%K hydrothermal synthesis method
%K structure type exhibits
%K Magnetic Ground State Crossover
%K Na 2 BaMn 0.6 Co 0.4
%K neutron powder diffraction
%K Mn 0.6 Co 0.4
%K C 4 axis
%X The
magnetic properties are reported for three members of the glaserite
series of compounds, Na2BaM(VO4)2, M = Mn, Mn0.6Co0.4, and Co. Large single
crystals are grown using a high-temperature hydrothermal synthesis
method. This structure type exhibits a triangular magnetic lattice
in which M2+O6 octahedra are interconnected
with nonmagnetic (VO4)3– groups. All
the structures crystallize at room temperature with rigid trigonal
symmetry (space group P3̅m1); however, at lower temperatures both Na2BaMn(VO4)2 and Na2BaMn0.6Co0.4(VO4)2 undergo a structural transition to lower
symmetry (monoclinic, C2/c). The
bulk magnetic measurements indicate that Mn- and Co-structures are
antiferromagnetic and ferromagnetic, respectively. Na2BaMn0.6Co0.4(VO4)2 does not show
any long-range ordering down to 0.5 K, although a broad heat capacity
anomaly near 1.2 K suggests short-range magnetic order or freezing
into a spin-glass-like state related to the chemical disorder and
resulting competing magnetic interactions. The magnetic structures
of Na2BaMn(VO4)2 and Na2BaCo(VO4)2 were determined using neutron powder
diffraction. At zero magnetic field, Na2BaMn(VO4)2 possesses an antiferromagnetic structure with the moments
ordered in a Néel-type arrangement and aligned along the C4 axis of the octahedra. Under applied magnetic field at 0.3
K, the evolution of the magnetic structure toward a fully polarized
state is observed. Na2BaCo(VO4)2 represents
a ferromagnetic (FM) magnetic structure with Co moments aligned parallel
to the c-axis direction. The relationships between
these structures and magnetic properties are discussed.
%I ACS Publications