Research/Sitter/MAGNDATA / 1.249_K2NiF4.mcif

K₂NiF₄

MAGNDATA entry 1.249 · 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 ≤ 190 K (−83 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	C_A m c a BNS 64.480
Parent space group	I 4/m m m No. 139
Spins	collinear · net moment 0 μ_B per cell
Propagation	[1/2 -1/2 0] 1k
Cell	a 5.6738 · b 5.6738 · c 13.076 Å · α 90° · β 90° · γ 90°
Transition	190 K (−83 °C)
Measured at	77 K
Magnetic ions	Ni
Largest moment component	1 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_A m c a →

Atom sites · 4 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
K1	K	0	0	0.3539
Ni1	Ni	0	0	0	0	0	1	1
F1	F	0	0	0.153
F2	F	0.25	0.25	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

R. Plumier et al. J. Phys. Radium (1963) · doi:10.1051/jphysrad:01962002308-9047400

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 1.249_K2NiF4.mcif from MAGNDATA · entry page

sha256 of this copy: 70063b4ed0fdb2d60a9eaff8d9f73f4e68908bb0bab62ef2baa9c40686d124c8
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 1.249_K2NiF4.mcif.