SQUID Magnetometry and Magneto-Optics of Epitaxial EuSe

• Authors: K. Rumpf , P. Granitzer , W. Kellner , R. Kirchschlager , S. Janecek , H. Pascher , H. Krenn
• Languages of publication: EN

Abstracts

EN

The complicated (H,T)-magnetic phase diagram of EuSe is caused by the critical balance between nearest and next nearest neighbour exchange interaction (J_{NN}=0.119 K and J_{NNN}=-0.1209 K) and leads to various spin arrangements NNSS..., NSN..., NNS, NNN... [NS denotes opposite ferromagnetic order in adjacent (111) planes]. Beside the subtle local exchange of 5d-t_{2g} electrons and localized holes with neighbouring Eu-4f spins, obviously also the strain status influences the occurrence of these different phases. We investigate the magnetic ordering phenomenon in a strained 2.5 μm EuSe film on BaF_2 substrate by SQUID magnetometry and magneto-optics like spectral Faraday- and Kerr-effect measurements for temperatures from 2 K up to 200 K and for magnetic fields up to 5 T. The magneto-optical probe monitors the local environment of the photoexcited electron-hole pair, called magnetic exciton, located within a ferromagnetic surrounding (photoinduced magnetic polaron), whereas the integral magnetization measured by SQUID is most sensitive to long-range magnetic ordering. In spite of the dissimilarity of measurement techniques we find an influence of the long-range magnetic order (e.g. of the NNS- or NNN-matrix) on the non-resonant Kerr reflection. The complementarity of SQUID and magneto-optical methods is stringent only in the (resonant) spectral regime, where magnetic polarons are formed.

Keywords

EN

75.50.Pp; 78.20.Ls; 07.55.Jg

Discipline

• 78.20.Ls: Magneto-optical effects(for magneto-optical devices, see 85.70.Sq)
• 07.55.Jg: Magnetometers for susceptibility, magnetic moment, and magnetization measurements
• 75.50.Pp: Magnetic semiconductors

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2004
• Volume: 105
• Issue: 6
• Pages: 621-629

Dates

published

2004-06

received

2004-05-28

Contributors

author

K. Rumpf

• Institut für Experimentalphysik, Universität Graz, 8010 Graz, Austria

author

P. Granitzer

• Institut für Experimentalphysik, Universität Graz, 8010 Graz, Austria

author

W. Kellner

• Experimentalphysik I, Universität Bayreuth, 95440 Bayreuth, Germany

author

R. Kirchschlager

• Institut für Halbleiter- u. Festkörperphysik, Universität Linz, 4040 Graz, Austria

author

S. Janecek

• Institut für Halbleiter- u. Festkörperphysik, Universität Linz, 4040 Graz, Austria

author

H. Pascher

• Experimentalphysik I, Universität Bayreuth, 95440 Bayreuth, Germany

author

H. Krenn

• Institut für Experimentalphysik, Universität Graz, 8010 Graz, Austria

References

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Identifiers

DOI

10.12693/APhysPolA.105.621