Magnetic and elastic properties of YCo5 and LaCo5 under pressure
Abstract
High hydrostatic pressure destroys the strong ferromagnetism in YCo5 . The transformation proceeds in a stepwise fashion, as a first-order phase transition (Pcrit=18±2GPa) , and is accompanied by an isomorphic (without change of symmetry) lattice collapse and a topological change of the Fermi surface. Accurate full-potential density-functional calculations enable us to ascribe these phenomena to a quasi-one-dimensional 3d -like band, whose top under ambient pressure is situated ∼0.1eV below the Fermi level. Lattice compression drives the top of the nondispersive band—and the associated peak in the majority density of states—upward in energy, until they reach the Fermi level and the system becomes unstable. A similar transition at a somewhat higher pressure (23GPa) is predicted for the isomorphous compound LaCo5 .
- Publication:
-
Physical Review B
- Pub Date:
- January 2008
- DOI:
- 10.1103/PhysRevB.77.024411
- Bibcode:
- 2008PhRvB..77b4411K
- Keywords:
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- 71.20.Lp;
- 75.30.Kz;
- 75.50.Cc;
- Intermetallic compounds;
- Magnetic phase boundaries;
- Other ferromagnetic metals and alloys