Research/Sitter/MAGNDATA / 1.223_Tm2CoGa8.mcif

Tm₂CoGa₈

MAGNDATA entry 1.223 · source

antiferromagnet

No net magnetisation, and up and down sublattices are related by a shift or by inversion, so the bands stay spin-degenerate: a conventional antiferromagnet.

Spin group ¹m¹m¹m × ²1: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 2 K (−271 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	C_ammm BNS 65.489
Parent space group	P 4/m m m No. 123
Spins	collinear · net moment 0 μ_B per cell
Propagation	[1/2 0 1/2] 1k
Cell	a 8.3796 · b 4.1898 · c 21.8218 Å · α 90° · β 90° · γ 90°
Transition	2 K (−271 °C)
Measured at	0.3 K
Magnetic ions	Tm
Largest moment component	2.35 μ_B
Method	NPD

Symmetry

Stereogram of the magnetic point group: each operation applied to one direction. Filled = upper hemisphere, ring = lower; red operations include time reversal. Lines are mirrors; polygons are 2/3/4/6-fold axes; the centre ring is inversion.

Every structure in C_ammm →

Atom sites · 7 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Tm1	Tm	0	0	0.1482	0	2.35	0	2.35
Co1	Co	0	0	0
Ga1_1	Ga	0	0.5	0.25
Ga1_2	Ga	0.25	0	0.25
Ga2	Ga	0.25	0.5	0.155
Ga3_1	Ga	0	0.5	0.0588
Ga3_2	Ga	0.25	0	0.0588

Moment components are along the crystal axes a, b, c (μ_B), as magCIF writes them. Symmetry generates the rest of the cell from these sites.

Source

R.D. Johnson et al. PHYSICAL REVIEW B (2010) · doi:10.1103/PhysRevB.82.104407

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.223_Tm2CoGa8.mcif from MAGNDATA · entry page

sha256 of this copy: 05a83da9bba47a1c90499b815c6869463ecbe620e0198dfd249e20a4863a6441
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.223_Tm2CoGa8.mcif.