Research/Sitter/MAGNDATA / 0.154_Er2Ru2O7.mcif

Er₂Ru₂O₇

MAGNDATA entry 0.154 · 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 ²4/¹m¹m²m: each symmetry marked ¹ keeps every spin, ² swaps up and down.

ordered ≤ 90 K (−183 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 11 properties

Magnetic group	I 4₁′/a m′ d BNS 141.554
Point group	4′/mm′m
Parent space group	F d 3m No. 227
Spins	collinear · 2 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 10.1063 · b 10.1063 · c 10.1063 Å · α 90° · β 90° · γ 90°
Transition	90 K (−183 °C)
Measured at	3 K
Magnetic ions	Er, Ru
Largest moment component	4.5 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 4₁′/a m′ d →

Atom sites · 5 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Er1	Er	0.5	0.5	0.5	4.5	0	0	4.5
Ru1	Ru	0	0	0	−2	0	0	2
O1_1	O	0.3358	0.125	0.125
O1_2	O	0.125	0.3358	0.125
O2	O	0.375	0.375	0.375

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

N. Taira et al. Journal of Solid State Chemistry (2003) · doi:10.1016/S0022-4596(03)00384-0

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.154_Er2Ru2O7.mcif from MAGNDATA · entry page

sha256 of this copy: 7cf99eb7c9aa1c4ec348e9346f0b7503b99cf67747618742b5d5d559f8187b9c
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.154_Er2Ru2O7.mcif.