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Itinerant magnetic excitations in antiferromagnetic CaFe2As2

Diallo, S. O.; Antropov, V. P.; Perring, T.G.; Broholm, C.; Pulikkotil, J. J.; Ni, N.; Bud'ko, S.L.; Canfield, P.C.; Kreyssig, A.; Goldman, A. I.; McQueeney, R. J. (American Physical Society, 2009-05-08)

Neutron scattering measurements of the magnetic excitations in single crystals of antiferromagnetic CaFe2As2 reveal steeply dispersive and well-defined spin waves up to an energy of ~100 meV. Magnetic excitations above 100 ...

From cooperative paramagnetism to Neel order in Y2Ru2O7: neutron scattering measurements

van Duijn, J.; Hur, N.; Taylor, J. W.; Qiu, Y.; Huang, Q.Z.; Cheong, S.-W.; Broholm, C.; Perring, T.G. (American Physical Society, 2008-01-01)

Spin correlations in the pyrochlore antiferromagnet Y2Ru2O7 with Curie-Weiss temperature ΘCW* - 1100 K and critical temperature TN = 77 K were examined through neutron scattering. For TN < T < ΘCW / 3 the data show spin ...

Field dependence of magnetic ordering in Kagome-staircase compound Ni3V2O8

Kenzelmann, M.; Harris, A. B.; Aharony, A.; Entin-Wohlman, O.; Yildirim, T.; Huang, Q.; Park, S.; Lawes, G.; Broholm, C.; Rogado, N.; Cava, R.J.; Kim, K. H.; Jorge, G.; Ramirez, A. P. (American Physical Society, 2006-07-01)

We present powder and single-crystal neutron diffraction and bulk measurements of the Kagome-staircase compound Ni3V2O8 (NVO) in fields up to 8.5 T applied along the c direction. (The Kagome plane is the a-c plane.) This ...

Phase diagram and spin Hamiltonian of weakly-coupled anisotropic S=½ chains in CuCl2·2((CD3)2SO)

Chen, Y.; Stone, M. B.; Kenzelmann, M.; Batista, C. D.; Reich, D.H.; Broholm, C. (American Physical Society, 2007-06-01)

Field-dependent specific heat and neutron scattering measurements were used to explore the antiferromagnetic S=½ chain compound CuCl2·2((CD3)2SO). At zero field the system acquires magnetic long-range order below TN=0.93 ...

Spin-trimer antiferromagnetism in La4Cu3MoO12

Qiu, Y.; Broholm, C.; Ishiwata, S.; Azuma, M.; Takano, M.; Bewley, R.; Buyers, W.J.L. (American Physical Society, 2005-06-01)

La4Cu3MoO12 is a cluster antiferromagnet where copper spin-1/2 trimers form a network of strongly coupled spin trimers. The magnetic properties of this material have been examined using magnetic neutron scattering. At low ...

Strong magnetic fluctuations in transition metal oxides

Aeppli, G.; Lee, S.-H.; Broholm, C.; DiTusa, J. F.; Bao, W. (American Institute of Physics, 1996-04-15)

Most magnets have long-range magnetic order when the thermal energy is less than the local magnetic exchange energy (T<|ΘCW|) effects such as reduced dimensionality and frustration, 1 however, can suppress the ordering ...

Quantum criticality in an organic magnet

Stone, M. B.; Broholm, C.; Reich, D.H.; Tchernyshyov, O.; Vorderwisch, P.; Harrison, N. (American Physical Society, 2006-06-30)

Exchange interactions between S=½ sites in piperazinium hexachlorodicuprate produce a frustrated bilayer magnet with a singlet ground state. We have determined the field-temperature phase diagram by high field magnetization ...

S=½ chain in a staggered field: high-energy bound-spinon state and the effects of a discrete lattice

Kenzelmann, M.; Batista, C. D.; Chen, Y.; Broholm, C.; Reich, D.H.; Park, S.; Qiu, Y. (American Physical Society, 2005-03-01)

We report an experimental and theoretical study of the antiferromagnetic S=½ chain subject to uniform and staggered fields. Using inelastic neutron scattering, we observe a bound-spinon state at high energies in the linear ...

Spinons in the strongly correlated copper oxide chains in SrCuO2

Broholm, C.; Perring, T.G.; Takagi, H.; Frost, C. D.; Zaliznyak, L.A.; Woo, H. (American Physical Society, 2004-08-20)

We have investigated the spin dynamics in the strongly correlated chain copper oxide SrCuO2 for energies up to ≥0.6 eV using inelastic neutron scattering. We observe a gapless continuum of magnetic excitations, which is ...

Longitudinal and perpendicular exchange bias in FeMn/(FeNi/FeMn)n multilayers

Sun, L.; Zhou, S.M.; Searson, P.C.; Chien, C.-L. (American Institute of Physics, 2003-05-15)

Exchange bias in ferromagnetic (FM)/antiferromagnetic (AF) bilayers is usually investigated in the longitudinal configuration with the exchange coupling established in the film plane. In this work, we report on the ...