Research/Sitter/MAGNDATA / 0.344_ErGe1.83.mcif

ErGe_1.83

MAGNDATA entry 0.344 · 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 ≤ 6 K (−267 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	C m c 2₁ BNS 36.172
Parent space group	C m c 2₁ No. 36
Spins	collinear · 2 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 4.0523 · b 29.485 · c 3.8846 Å · α 90° · β 90° · γ 90°
Transition	6 K (−267 °C)
Measured at	1.5 K
Magnetic ions	Er
Largest moment component	7.63 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 · 6 sites · CSV

site	element	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Er1	Er	0.0609	0.75	7.63	0	0	7.63
Er2	Er	0.171	0.249	−7.63	0	0	7.63
Ge1	Ge	0.3529	0.268
Ge2	Ge	0.4074	0.744
Ge3	Ge	0.2499	0.765
Ge4	Ge	0.5101	0.347

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

O. Oleksyn et al. “Journal (1997) · doi:10.1016/S0925-8388(96)02714-4

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.344_ErGe1.83.mcif from MAGNDATA · entry page

sha256 of this copy: 8d327c68ae23566db21728d3011a037d00da5fddeb13898480029838b023497b
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.344_ErGe1.83.mcif.