Research/Sitter/MAGNDATA / 0.418_K0.8Fe1.8Se2.mcif

K_0.8Fe_1.8Se₂

MAGNDATA entry 0.418 · 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 ¹4/¹m × ²1: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 559 K (286 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	I 4/m′ BNS 87.78
Parent space group	I 4/m No. 87
Spins	collinear · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 8.6929 · b 8.6929 · c 14.0168 Å · α 90° · β 90° · γ 90°
Transition	559 K (286 °C)
Measured at	11 K
Magnetic ions	Fe
Largest moment component	3.31 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 I 4/m′ →

Atom sites · 6 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
K1	K	0	0	0.5
K2	K	0.404	0.178	0
Fe1	Fe	0	0.5	0.25
Fe2	Fe	0.1979	0.0915	0.2467	0	0	3.31	3.31
Se1	Se	0.5	0.5	0.1337
Se2	Se	0.1147	0.3011	0.1455

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. Bao et al. CHIN. PHYS. LETT. (2011) · doi:10.1088/0256-307X/28/8/086104

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.418_K0.8Fe1.8Se2.mcif from MAGNDATA · entry page

sha256 of this copy: 471fab154ebcb8409b6040383d08996d166f63495bea617fcb97cfcd6d1d78f9
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.418_K0.8Fe1.8Se2.mcif.