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in creator/contributor: "Christianson, A.D."  
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Radiation imaging technology for nuclear materials safeguards

Description: Gamma-ray and neutron imaging technology is emerging as a useful tool for nuclear materials safeguards. Principal applications include improvement in accuracy for nondestructive assay of heterogeneous material (e.g., residues) and wide-area imaging of nuclear material in facilities (e.g., holdup). Portable gamma cameras with gamma-ray spectroscopy are available commercially and are being applied to holdup measurements. The technology has the potential to significantly reduce effort and exposure… more
Date: December 1, 1997
Creator: Prettyman, T. H.; Russo, P. A.; Cheung, C. C.; Christianson, A. D.; Feldman, W. C. & Gavron, A.
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Partner: UNT Libraries Government Documents Department
open access

Magnetotransport studies of cerium iridium indium (5) and cerium cobalt indium(5).

Description: Magnetotransport measurements have shed additional light on the behavior of CeRhIn5.[1] In an effort to more fully understand the systematic relationship between CeRhIns and the other members of the CeMIn5 (M = Co, Rh, Ir) series of heavy fermion superconductors we have extended our studies to CeCoIns and CeIrIn5 . To that end, we have investigated the magnetotransport in Ce-based heavy fermion superconductors CeIrIns and CeCoIn5 from 1 .4 - 300 K as a function of applied magnetic fields to 18 … more
Date: January 1, 2003
Creator: Christianson, A. D. (Andrew D.); Lacerda, A. H. (Alex H.); Pagliuso, P. J. (Pascoal J.); Sarrao, John L., & Kern, S.
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Partner: UNT Libraries Government Documents Department
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Ytterbium divalency and lattice disorder in near-zero thermalexpansion YbGaGe

Description: While near-zero thermal expansion (NZTE) in YbGaGe is sensitive to stoichiometry and defect concentration, the NZTE mechanism remains elusive. We present x-ray absorption spectra that show unequivocally that Yb is nearly divalent in YbGaGe and the valence does not change with temperature or with 1% B or 5% C impurities, ruling out a valence-fluctuation mechanism. Moreover, substantial changes occur in the local structure around Yb with B and C inclusion. Together with inelastic neutron scatteri… more
Date: May 8, 2006
Creator: Booth, C. H.; Christianson, A. D.; Lawrence, J. M.; Pham, L.; Lashley, J. & Drymiotis, F. R.
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Partner: UNT Libraries Government Documents Department
open access

Coexistence of antiferromagnetic order and superconductivity in CeRh[sub 1[minus]x]M[sub x]In[sub 5](M=Ir and Co)

Description: We report a systematic neutron diffraction study on the coexistence of long-range magnetic order and superconductivity in heavy fermion compounds CeRhl-,M,Ins (M=Ir,Co). In addition to the incommensurate antiferromagnetic component in pure CeRhIn5, new type of antiferromagnetic component is found to concur with appearance of superconductivity in the Ir and Co alloy series. There is no detectable effect of the superconducting transition on magnetic order parameters. We compare those results with… more
Date: December 4, 2002
Creator: Llobet-Megias, A. (Anna); Christianson, A. D. (Andrew D.); Bao, W. (Wei); Gardner, J. S.; Pagliuso, P. J. (Pascoal J.); Moreno, N. O. et al.
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Partner: UNT Libraries Government Documents Department
open access

Antiferromagnetism in Pr3In: Singlet/triplet physics withfrustration

Description: We present neutron diffraction, magnetic susceptibility and specific heat data for a single-crystal sample of the cubic (Cu{sub 3}Au structure) compound Pr{sub 3}In. This compound is believed to have a singlet ({Lambda}{sub 1}) groundstate and a low-lying triplet ({Lambda}{sub 4}) excited state. In addition, nearest-neighbor antiferromagnetic interactions are frustrated in this structure. Antiferromagnetic order occurs below T{sub N} = 12K with propagation vector (0, 0, 0.5 {center_dot}{delta})… more
Date: November 18, 2004
Creator: Christianson, A. D.; Lawrence, J. M.; Zarestky, J. L.; Suzuki, H.; Thompson, J. D.; Hundley, M. F. et al.
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Partner: UNT Libraries Government Documents Department
open access

Anisotropic intermediate valence in Yb2M3Ga9 (M = Rh, Ir)

Description: The intermediate valence compounds Yb{sub 2}M{sub 3}Ga{sub 9} (M = Rh, Ir) exhibit an anisotropic magnetic susceptibility. We report measurements of the temperature dependence of the 4f occupation number, n{sub f}(T), for Yb{sub 2}M{sub 3}Ga{sub 9} as well as the magnetic inelastic neutron scattering spectrum S{sub mag}({Delta}E) at 12 and 300 K for Yb{sub 2}Rh{sub 3}Ga{sub 9}. Both n{sub f}(T) and S{sub mag}({Delta}E) were calculated for the Anderson impurity model with crystal field terms wit… more
Date: April 26, 2005
Creator: Christianson, A. D.; Lawrence, J. M.; Lobos, A. M.; Aligia, A. A.; Bauer, E. D.; Moreno, N. O. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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