Abstract
We report on the doping dependence of the order of the ferromagnetic metal to paramagnetic insulator phase transition in . At , magnetization and specific heat data show a first order transition, with an entropy change () accounted for by both volume expansion and the discontinuity of via the Clausius-Clapeyron equation. At , the data show a continuous transition with tricritical point exponents , , , and . This tricritical point separates first- () from second-order () transitions.
- Received 20 June 2002
DOI:https://doi.org/10.1103/PhysRevLett.89.227202
©2002 American Physical Society