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Studies of deposition order anomaly of exchange coupling in bilayers and trilayers of NiFe and CoO

Ambrose, T.; Leifer, K.; Hemker, K. J.; Chien, C. L. (American Institute of Physics, 1997-04-15)

The temperature dependence of the exchange field and coercivity and the effect of deposition order have been studied in a series of bilayer (NiFe/CoO and CoO/NiFe) and trilayer (NiFe/CoO/NiFe) films. A profound difference ...

Neutron scattering evidence for isolated spin-1/2 ladders in (C5D12N)2CuBr4

Nagler, S. E.; Pajerowski, D. M.; Meisel, M. W.; Broholm, C.; Schmidt, K. P.; Talham, D. R.; Brown, C.M.; Uhrig, G. S.; Savici, A.T.; Granroth, G. E. (American Physical Society, 2009-09-01)

Inelastic neutron scattering was used to determine the spin Hamiltonian for the singlet ground-state system of fully deuterated BPCB, (C5D12N)2CuBr4. A two-leg spin-1/2 ladder model, with J⊥=(1.09±0.01) meV and J∥=(0.296±0.005) ...

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-lattice order in frustrated ZnCr2O4

Ji, S.; Lee, S.-H.; Broholm, C.; Koo, T. Y.; Ratcliff, W.; Cheong, S.-W.; Zschack, P. (American Physical Society, 2009-07-17)

Using synchrotron x-ray and neutron diffraction, we disentangle spin-lattice order in highly frustrated ZnCr2O4 where magnetic chromium ions occupy the vertices of regular tetrahedra. Upon cooling below 12.5 K the quandary ...

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 ...

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 ...

Neutron scattering from a coordination polymer quantum paramagnet

Hong, T.; Kenzelmann, M.; Turnbull, M. M.; Landee, C. P.; Lewis, B.D.; Schmidt, K. P.; Uhrig, G. S.; Broholm, C.; Reich, D. (American Physical Society, 2006-09-01)

Inelastic neutron scattering measurements are reported for a powder sample of the spin-1/2 quantum paramagnet Cu(quinoxaline)Br2. Magnetic neutron scattering is identified above an energy gap of 1.9 meV. Analysis of the ...

Anisotropic three-dimensional magnetism in CaFe2As2

McQueeney, R. J.; Diallo, S. O.; Antropov, V. P.; Samolyuk, G. D.; Broholm, C.; Ni, N.; Nandi, S.; Yethiraj, M.; Zaretsky, J.L.; Pulikkotil, J. J.; Kreyssig, A.; Lumsden, M.D.; Harmon, B. N.; Canfield, P.C. (American Physical Society, 2008-11-28)

Inelastic neutron scattering measurements of the magnetic excitations in CaFe2As2 indicate that the spin wave velocity in the Fe layers is exceptionally large and similar in magnitude to the cuprates. However, the spin ...

Exchange coupling between Cr and ferromagnetic thin films

Yang, F.Y.; Chien, C.-L. (American Institute of Physics, 2003-05-15)

Exchange bias has been observed in Ni81Fe19/Cr bilayers. The exchange bias field for Cr thickness tCr larger than 62 Å increases with tCr and levels off at tCr=150 Å, whereas coercivity increases without saturation. The ...