Research/Sitter/MAGNDATA / 0.65_Fe2O3-alpha.mcif

Fe₂O₃-alpha

MAGNDATA entry 0.65 · source

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.

Spin group ¹3̄²m: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 955 K (682 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	C 2′/c′ BNS 15.89
Point group	2′/m′
Parent space group	R 3c No. 167
Spins	collinear · 3 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 5.035128 · b 5.035128 · c 13.75809 Å · α 90° · β 90° · γ 120°
Transition	955 K (682 °C)
Measured at	300 K
Magnetic ions	Fe
Largest moment component	4.118 μ_B
Method	weak ferromagnetic component along the (1,2,0) direction, perpendicular to the x direction of about 0.004 muB, not explicitly included in the model.

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 2′/c′ →

Atom sites · 3 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Fe1	Fe	0	0	0.3553	4.118	0	0	4.118
O1_1	O	0.3062	0	0.25
O1_2	O	0	0.3062	0.25

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

A.H. Hill et al. Chem. Mater. (2008) · doi:10.1021/cm800009s

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.65_Fe2O3-alpha.mcif from MAGNDATA · entry page

sha256 of this copy: 65b114fc964c3e463c89dd0363c08760bd1deecbc1302d3e45cc3467a266e959
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.65_Fe2O3-alpha.mcif.