Research/Sitter/MAGNDATA / 0.999_Fe4O5.mcif

Fe₄O₅

MAGNDATA entry 0.999 · 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 ¹m²m²m: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 320 K (47 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	C m′ c 2₁′ BNS 36.174
Point group	m′m2′
Parent space group	C m c m No. 63
Spins	collinear · 2 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 2.8906 · b 9.8024 · c 12.5804 Å · α 90° · β 90° · γ 90°
Transition	320 K (47 °C)
Measured at	150 K
Magnetic ions	Fe
Largest moment component	3 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 m′ c 2₁′ →

Atom sites · 9 sites · CSV

site	element	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Fe1	Fe	0.5052	0.25	0	0	−3	3
Fe2	Fe	0	0	0	0	3	3
Fe3_1	Fe	0.2604	0.1174	0	0	3	3
Fe3_2	Fe	0.2604	0.3826	0	0	3	3
O1_1	O	0.359	0.5442
O1_2	O	0.359	0.9558
O2	O	0.1601	0.25
O3_1	O	0.093	0.6422
O3_2	O	0.093	0.8578

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

S. V. Ovsyannikov et al. Nature Chemistry (2016) · doi:10.1038/nchem.2478

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.999_Fe4O5.mcif from MAGNDATA · entry page

sha256 of this copy: 15983b9a14099a09add5179f4792f4cf471c9598c0df87aa4167ffa6758373a5
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.999_Fe4O5.mcif.