Magnetic interactions in the multiferroic phase of CuFe1 xGaxO2 (x = 0.035) refined by inelastic neutron scattering with uniaxial-pressure control of domain structure

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.85.144405· OSTI ID:1039624

Nakajima, Taro ^[1]; Mitsuda, Setsuo ^[1]; Haraldsen, Jason T. ^[2]; Fishman, Randy Scott ^[3]; Hong, Tao ^[3]; Terada, Noriki ^[4]; Uwatoko, Yoshiya ^[5]

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1. Tokyo University of Science, Japan
2. Los Alamos National Laboratory (LANL)
3. ORNL
4. National Institute for Materials Science, Tsukuba, Japan
5. University of Tokyo, Tokyo, Japan

We have performed inelastic neutron scattering measurements in the ferroelectric noncollinear- magnetic phase of CuFe1 xGaxO2 (CFGO) with x = 0.035 under applied uniaxial pressure. This system has three types of magnetic domains with three different orientations reflecting the trigonal symmetry of the crystal structure. To identify the magnetic excitation spectrum corresponding to a magnetic domain, we have produced a nearly single-domain multiferroic phase by applying a uniaxial pressure of 10 MPa onto the [1 10] surfaces of a single crystal CFGO sample. As a result, we have successfully observed the single-domain spectrum in the multiferroic phase. Using the Hamiltonian employed in the previous inelastic neutron scattering study on the multi-domain multiferroic phase of CFGO (x = 0.035) [Haraldsen et al. Phys. Rev. B 82 020404R (2010)], we have refined the Hamiltonian parameters so as to simultaneously reproduce both of the observed single-domain and multi-domaim spectra. Comparing between the Hamiltonian parameters in the multiferroic phase of CFGO and in the collinear four-sublattice magnetic ground state of undoped CuFeO2 [Nakajima et al, Phys. Rev. B 84 184401 (2011)], we suggest that the nonmagnetic substitution weakens the spin-lattice coupling, which often favors a collinear magnetic ordering, as a consequence of the partial release of the spin frustration.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1039624
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 14 Vol. 85; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CRYSTAL STRUCTURE
DOMAIN STRUCTURE
EXCITATION
GROUND STATES
HAMILTONIANS
MONOCRYSTALS
NEUTRONS
SCATTERING
SPECTRA
SPIN
SYMMETRY