Research/Sitter/MAGNDATA / 0.178_CoF2.mcif

CoF₂

MAGNDATA entry 0.178 · source

d-wave altermagnet

No net magnetisation, yet the electron bands are spin-split: the up and down spin sublattices are related only by a rotation or mirror, never by a shift or inversion. d-wave: the splitting changes sign twice around the Fermi surface (2 nodal planes).

Spin group ²4/¹m²m¹m: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 39 K (−234 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	P4₂′/mnm′ BNS 136.499
Parent space group	P 4₂/m n m No. 136
Spins	collinear · 2 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 4.6941 · b 4.6941 · c 3.1698 Å · α 90° · β 90° · γ 90°
Transition	39 K (−234 °C)
Measured at	15 K
Magnetic ions	Co
Largest moment component	2.6 μ_B
Method	SCND

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 P4₂′/mnm′ →

Atom sites · 2 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Co1	Co	0	0	0	0	0	2.6	2.6
F1	F	0.3032	0.3032	0

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

W. Jauch et al. Acta Crystallographica A (2004) · doi:10.1107/S0108767303022803

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.178_CoF2.mcif from MAGNDATA · entry page

sha256 of this copy: 60587877d40cfbdd4111320ec1551d5ec83be3660e2cad74d9a4babf12725a23
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.178_CoF2.mcif.