Neutron Brillouin Scattering with Pulsed Spallation Neutron Source —Spin-Wave Excitations from Ferromagnetic Powder Samples—

The neutron Brillouin scattering (NBS) method, which was developed using advanced neutron sources, was extended to an intense pulsed spallation neutron source. The feasibility of this method was demonstrated by observing ferromagnetic spin waves in La0.8Sr0.2MnO3 and SrRuO3 powders. Gapless spin-wave excitations were observed in La0.8Sr0.2MnO3, which were continuously extrapolated to the lower scattering vector \(Q\) from previous results using single crystals. The novel result is a well-defined quadratic \(Q\) dependence in the spin-wave dispersion curve with a large energy gap in SrRuO3.

[1]  Taku J. Sato,et al.  Data acquisition system for high resolution chopper spectrometer (HRC) at J-PARC , 2011 .

[2]  Taku J. Sato,et al.  High Resolution Chopper Spectrometer (HRC) at J-PARC , 2011 .

[3]  J. Orenstein,et al.  Observation of ferromagnetic resonance in SrRuO3 by the time-resolved magneto-optical Kerr effect. , 2009, Physical review letters.

[4]  S. Petit,et al.  Spin waves in the ferromagnetic metallic manganitesLa1−x(Ca1−ySry)xMnO3 , 2007 .

[5]  D. Aisa,et al.  BRISP: A new thermal-neutron spectrometer for small-angle studies of disordered matter , 2006 .

[6]  Y. Endoh,et al.  Magnetic Excitations in Metallic Ferro- and Antiferromagnets , 2006 .

[7]  M. Beasley,et al.  Large anisotropy in the paramagnetic susceptibility of SrRuO$_{3}$ films , 2003, cond-mat/0311341.

[8]  T. Ogasawara,et al.  The Anomalous Hall Effect and Magnetic Monopoles in Momentum Space , 2003, Science.

[9]  T. M. Kelley,et al.  Observation of transverse phonon modes in the first Brillouin zone in aluminum , 1997 .

[10]  Y. Endoh,et al.  Scaling of Spin-Wave Stiffness Constant to Curie Temperature in the Colossal Magnetoresistance Material La1-xSrxMnO3. , 1997 .

[11]  Klein,et al.  Anomalous Spin Scattering Effects in the Badly Metallic Itinerant Ferromagnet SrRuO3. , 1996, Physical review letters.

[12]  C. Carlile,et al.  Angular and time resolution of neutron time of flight spectrometers , 1995 .

[13]  K. Tajima,et al.  Spin Dynamics in the Amorphous Invar Alloy of Fe86B14 , 1981 .

[14]  J. Als-Nielsen,et al.  Neutron scattering from the Heisenberg ferromagnets EuO and EuS. I. The exchange interactions , 1976 .

[15]  R. E. Watson,et al.  Hartree–Fock atomic scattering factors for the iron transition series , 1961 .

[16]  M. Beasley,et al.  Structure, physical properties, and applications of SrRuO3 thin films , 2012 .

[17]  R. Robinson.  Neutron Brillouin scattering with chopper spectrometers , 1989 .