Tricritical Behavior in KMnF3

The cubic-to-tetragonal structural phase transition of KMn${\mathrm{F}}_3$ has been investigated by measurement of the phase diagrams with uniaxial pressure along [110] and [100]. Results indicate the existence of a tricritical point near $p=0.45\mathrm{}$ kbar with $p$ along [110], and two new consecutive tricritical points near $p=0.25\mathrm{}$ kbar with $p$ along [100].