Work

Magnetoelectronic properties of a ferrimagnetic semiconductor: The hybrid cupromanganite CaCu3Mn4O12

Year: 2001

Type: article

Abstract: The mixed manganite cuprate ${\mathrm{CaCu}}_{3}{\mathrm{Mn}}_{4}{\mathrm{O}}_{12}$ is calculated, using density functional methods, to be a spin-asymmetric ferrimagnetic semiconductor with a small gap. Cu (formally spin $\frac{1}{2})$ antialigns with Mn (formally spin $\frac{3}{2}),$ and the net spin moment is $9{\ensuremath{\mu}}_{B},$ consistent with the formal spins. The valence-band maximum has Cu ${d}_{\mathrm{xy}}--\mathrm{O}$ ${p}_{\ensuremath{\sigma}}$ character with spin aligned antiparallel with the net magnetization; the conduction-band minimum has the opposite spin and mixed Cu-Mn character. This spin-asymmetric gap (1) implies a thermally induced current that is 100% spin polarized and (2) leads to a field-induced narrowing of the energy gap. The relationship of these properties to the reported magnetoresistance is discussed.

Source: Physical review. B, Condensed matter

DOI: 10.1103/physrevb.65.014415

Authors: Ruben Weht, Warren E. Pickett

Institutions: Comisión Nacional de Energía Atómica, University of California, Davis

Language: English

Topic: Magnetic and transport properties of perovskites and related materials

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, Office of Naval Research, Division of Materials Research

Award: First Principles Theory of Complex Compounds