First Order Transitions and Multicritical Points in Weak Itinerant Ferromagnets
Abstract
It is shown that the phase transition in low- Tc clean itinerant ferromagnets is generically of first order, due to correlation effects that lead to a nonanalytic term in the free energy. A tricritical point separates the line of first order transitions from Heisenberg critical behavior at higher temperatures. Sufficiently strong quenched disorder suppresses the first order transition via the appearance of a critical end point. A semiquantitative discussion is given in terms of recent experiments on MnSi, and predictions for other experiments are made.
- Publication:
-
Physical Review Letters
- Pub Date:
- June 1999
- DOI:
- 10.1103/PhysRevLett.82.4707
- arXiv:
- arXiv:cond-mat/9812420
- Bibcode:
- 1999PhRvL..82.4707B
- Keywords:
-
- Condensed Matter - Statistical Mechanics;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 4 pp., REVTeX, epsf, 3 eps figs, final version as published