MAGNDATA - Collection of Magnetic Structures

MAGNDATA

Collection of Magnetic Structures

MAGNDATA: A Collection of magnetic structures with portable cif-type files

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Magnetic structure with all atoms

Magnetic structure with only magnetic atoms

N	(x,y,z)	Seitz notation
1	x,y,z,+1	{ 1 \| 0 }
2	-x+1/2,-y+1/2,-z+1/2,+1	{ -1 \| 1/2 1/2 1/2 }
(1/2,1/2,1/2)' + set click here to show and hide
3	x+1/2,y+1/2,z+1/2,-1	{ 1' \| 1/2 1/2 1/2 }
4	-x,-y,-z,-1	{ -1' \| 0 }

N	(x,y,z)	Seitz notation
1	x,y,z,+1	1
2	-x,-y,-z,+1	-1
1' + set click here to show and hide
3	x,y,z,-1	1'
4	-x,-y,-z,-1	-1'

Label	Atom type	x	y	z	Multiplicity
Sc1_1	Sc	0.00000	0.50000	0.00000	2
Sc1_2	Sc	0.50000	0.00000	0.00000	2
Ge1	Ge	0.007(1)	0.996(1)	0.1207(8)	4

Atom	x	y	z	Symmetry constraints on M	M_x	M_y	M_z
1	0.98900	0.01000	0.32330	m_x,m_y,m_z	0.60000	0.60000	1.15000
2	0.51100	0.49000	0.17670	m_x,m_y,m_z	0.60000	0.60000	1.15000
(1/2,1/2,1/2)' + set click here to show and hide
3	0.48900	0.51000	0.82330	-m_x,-m_y,-m_z	-0.60000	-0.60000	-1.15000
4	0.01100	0.99000	0.67670	-m_x,-m_y,-m_z	-0.60000	-0.60000	-1.15000

Atom	x	y	z
1	0.00000	0.50000	0.00000
(1/2,1/2,1/2)' + set click here to show and hide
2	0.50000	0.00000	0.50000

Atom	x	y	z
1	0.50000	0.00000	0.00000
(1/2,1/2,1/2)' + set click here to show and hide
2	0.00000	0.50000	0.50000

Atom	x	y	z
1	0.00700	0.99600	0.12070
2	0.49300	0.50400	0.37930
(1/2,1/2,1/2)' + set click here to show and hide
3	0.50700	0.49600	0.62070
4	0.99300	0.00400	0.87930

Reference: C. Ritter, A. Provino, P. Manfrinetti and A.K. Pathak, Journal of Physics: Condensed Matter (2016) 29 045802.
DOI: 10.1088/1361-648x/29/4/045802
Atomic positions from: ICSD #257404

Parent space group (paramagnetic phase): I4/mmm (#139)
Propagation vector: k1 (1, 1, 1)

Transition Temperature: 36 K
Experiment Temperature: 5 K

Lattice parameters of the magnetic unit cell:
4.3359(3) 4.3347(3) 15.9628(3) 90.22(1) 90.26(4) 89.992(2)
Transformation from parent structure: (a,b,c;0,0,0)
    [View matrix form]

BNS Magnetic Space Group: P_S-1 (#2.7) (non-standard)
    [View symmetry operations]
Transformation to a standard setting: (-c,b,a-b+3c;1/4,1/4,1/4)
    [View matrix form]
Systematic absences for this Magnetic Space Group via

Magnetic Point Group: -1.1' (2.2.4)
    [View symmetry operations]
Symmetry-adapted form of material tensors via
Symmetry-adapted form of material tensors for domain-related equivalent structures via

Positions and magnetic moments of symmetry independent atoms:
From now on, magnetic atoms are in boldface and colored in red. Magnetic moments are expressed in units of μB

     [Show only magnetic atoms]                                             Use MVISUALIZE to:
     [Show all the atoms]

Label	Atom type	x	y	z	Multiplicity	Symmetry constraints on M	M_x	M_y	M_z	\|M\|
Ce1	Ce	0.989(2)	0.010(2)	0.3233(1)	4	m_x,m_y,m_z	0.60(1)	0.6	1.15(4)	1.43

Atom	x	y	z	Symmetry constraints on M	M_x	M_y	M_z
1	0.98900	0.01000	0.32330	m_x,m_y,m_z	0.60000	0.60000	1.15000
2	0.51100	0.49000	0.17670	m_x,m_y,m_z	0.60000	0.60000	1.15000
(1/2,1/2,1/2)' + set click here to show and hide
3	0.48900	0.51000	0.82330	-m_x,-m_y,-m_z	-0.60000	-0.60000	-1.15000
4	0.01100	0.99000	0.67670	-m_x,-m_y,-m_z	-0.60000	-0.60000	-1.15000

[Show all magnetic atoms in unit cell and their moment relations]

Active Irreps:

label	dim. full irrep	dim. small irrep	direction	action	number of modes
mM5-	2	2	general	primary	1
mM1-	1	1		primary	1

Comments:

NPD
Between 48K and 36K another magnetic phase is reported with the moments on the basal plane (see #1.376)
Strong magnetostructural effect with a magnetic induced strain

Comments (symmetry):

1k magnetic structure
Two irreps are active as primary, i.e. two order parameters are necessary in the sense of Landau theory.
The other magnetic structure at higher temperature with the moments on the ab plane is associated a single order parameter according to one of the two irreps: mM5- (see #1.376)
The magnetic ordering of this model only reduces the parent symmetry into a monoclinc MSG, as the mM5- ordering is along a special direction. The monoclinic axis is along the (-1,1,0) direction of the parent structure. The unit cell strain of the reported triclinic unit cell with respect to the tetragonal one complies within its tolerances with monoclinic symmetry.
The reduction from monoclinic into a a triclinic symmetry is only produced by small displacements on the xy plane of the Ce1 and Ge1 atoms, from their (0,0,z) parent positions.
This small atomic displacements, which break further the symmetry, cannot be considered an induced effect of the magnetic ordering. It is either an artefact of the model or an additional symmetry-breaking structural distortion, i.e. a additional independent order parameter.
An older version (30/04/2020) of this entry has been corrected.

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MAGNDATA: A Collection of magnetic structures with portable cif-type files

CeScGe (#1.375)