Dicalcium ruthenate

Dicalcium ruthenate, with the chemical formula Ca₂RuO₄, is a stochiometric oxide compound that hosts a multi-orbital (band) Mott insulating ground state. For this reason, Ca₂RuO₄ serves as an important "meeting-point" between conceptual developments^[1][2] of strongly correlated multi-band physics and advanced experimental spectroscopies.^[3][4] Its electronic structure and also orbital magnetism are therefore subjects of experimental and theoretical scrutiny.

Dicalcium ruthenate

Identifiers
3D model (JSmol)	Interactive image
InChI InChI=1S/2Ca.O4Ru/c;;1-5(2,3)4/q2*+2;-4 Key: JWAHTWBBWFKEMH-UHFFFAOYSA-N
SMILES [Ca+2].[Ca+2].[O-][Ru]([O-])([O-])[O-]
Properties
Chemical formula	Ca2O4Ru
Molar mass	245.22 g·mol−1
Related compounds
Other cations	Distrontium ruthenate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Electronic properties

Around 350 K, Ca₂RuO₄ undergoes a metal insulator transition which involves a crystal structure transition leading to a strong c-axis compression. Negative thermal expansion has also been reported in conjunction with this c-axis compression.^[5] The metal insulator transition is sensitive to electrical current.^[6][7] Below 80 K, an anti-ferromagnetic ordering emerges.

Related materials

Ca_1.8Sr_0.2RuO₄ has been proposed as a candidate system for orbital selective Mott physics.^[8] The bilayer compound Ca₃Ru₂O₇ is metallic, but display a sequence of electronic transitions below 60 K. Finally, Sr₂RuO₄ hosts an unconventional superconducting state.^[9]