Invar Like Behavior of the Cr 2 AlC MAX Phase at Low Temperature
Abstract
The structure of Cr AlC has been studied using neutron scattering experiments performed in a
temperature range running from room temperature down to 1.8 K. It is shown that the unit cell volume
does not vary significantly below 80 K. This anomalous behavior, correlated with the existence of a
weak ferromagnetic ordering revealed from superconducting quantum interference device experiments,
is similar to that characteristic of Invar alloys. Just above the Curie temperature T ~ 73 ± 5 K, the
Cr AlC undergoes significant distortions of the octahedron and triangular prisms units. Above 100 K,
Cr AlC follows an usual thermal expansion.