Research/Sitter/MAGNDATA / 0.202_Ca2PrCr2TaO9.mcif

Ca₂PrCr₂TaO₉

MAGNDATA entry 0.202 · 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 ≤ 130 K (−143 °C)Colour: where that sits relative to 25 °C. Saturation: how much margin it has.

Structure · 10 properties

Magnetic group	P n′ m′ a BNS 62.446
Parent space group	P n m a No. 62
Spins	collinear · 2 nodal planes · net moment 0 μ_B per cell
Propagation	[0 0 0] 1k
Cell	a 5.49132 · b 7.7091 · c 5.42625 Å · α 90° · β 90° · γ 90°
Transition	130 K (−143 °C)
Measured at	5 K
Magnetic ions	Cr
Largest moment component	2 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 P n′ m′ a →

Atom sites · 6 sites · CSV

site	element	x	y	z	m_a	m_b	m_c	\|m\| (μ_B)
Ca1	Ca	0.0373	0.25	0.9914
Pr1	Pr	0.0373	0.25	0.9914
Cr1	Cr	0	0	0.5	0	2	0	2
Ta1	Ta	0	0	0.5
O1	O	0.4819	0.25	0.0752
O2	O	0.2087	0.54	0.2073

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

E.C. Hunter et al. J. Solid State Chem. (2019) · doi:10.1016/j.jssc.2018.09.012

Cite the original paper and MAGNDATA, not this mirror.

Original file

⬇ 0.202_Ca2PrCr2TaO9.mcif from MAGNDATA · entry page

sha256 of this copy: daca9a29a92152df1d142bcbc4525fc3ac89001c78786a4a4d91f7052d5b57cb
The mirror keeps the bytes Bilbao served, so the original should hash the same unless MAGNDATA has revised the entry since: shasum -a 256 0.202_Ca2PrCr2TaO9.mcif.