Lifshitz Point in MnP

Measurements of the transverse differential susceptibility in MnP suggest that the para-ferro-fan triple point is a Lifshitz point (LP). At this point all phase boundaries are tangent to each other, and the $\lambda$ line exhibits an inflection point. These features agree with predictions for a LP characterized by $d=3\mathrm{}$, $n=m=1\mathrm{}$, which is expected for this crystal symmetry. A crossover exponent $\phi =0.634\mathrm{}\pm 0.03$ is obtained, in agreement with theory.