## LSU Historical Dissertations and Theses

#### Title

Magnetism in BCC and FCC Manganese.

1987

Dissertation

#### Degree Name

Doctor of Philosophy (PhD)

#### Department

Physics and Astronomy

Joseph Callaway

#### Abstract

The electronic band structure, magnetic moment, and density of states of bcc and fcc manganese are calculated as a function of the lattice constant, using the LCGO method, on the local density approximation. For bcc manganese, two magnetic phases were found: a low moment state (m $\simeq$ 1 $\mu\sb{\rm B}$) and a high moment state (m $\ge$ 2.4 $\mu\sb{\rm B}$). For a small range of lattice constants (a = 5.9 to 6.025 a.u.), two local minima of the energy can coexist, yielding two different values of the moment for the same lattice constant. For fcc manganese, two phases were found: a zero moment state for a less than about 7.25 a.u. and a high moment state (m $\ge$ 1.88 $\mu\sb{\rm B}$). Both phase transitions are described in detail in terms of the band structure.

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