Research/Sitter/MAGNDATA / 0.747_Ba3CoIr2O9.mcif

Ba₃CoIr₂O₉

MAGNDATA entry 0.747 · 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 ²2/²m: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 107 K (−166 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	C 2/c BNS 15.85
Point group	2/m
Parent space group	C 2/c No. 15
Spins	collinear · 1 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 5.734 · b 9.9841 · c 14.2652 Å · α 90° · β 90.04° · γ 90°
Transition	107 K (−166 °C)
Measured at	80 K
Magnetic ions	Co, Ir
Largest moment component	2.45 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 2/c →

Atom sites · 9 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Ba1	Ba	0.0004	0.3312	0.0877
Ba2	Ba	0	0.9994	0.25
Co1	Co	0	0	0	0	0	2.45	2.45
Ir1	Ir	0.994	0.3337	0.8462	0	0	0.57	0.57
O1	O	0	0.503	0.25
O2	O	0.2662	0.2414	0.2381
O3	O	0.0296	0.8401	0.0805
O4	O	0.2567	0.1003	0.0814
O5	O	0.7709	0.0744	0.0784

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

C. Garg et al. PHYSICAL REVIEW B (2021) · doi:10.1103/PhysRevB.103.014437

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.747_Ba3CoIr2O9.mcif from MAGNDATA · entry page

sha256 of this copy: 8a64f0a11fe9313c9acf1d467aa1265feaffed39efa58d8334b890437aa9de75
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.747_Ba3CoIr2O9.mcif.