Bauer, R.*; Tse, J. S.*; Komatsu, Kazuki*; Machida, Shinichi*; Hattori, Takanori
Nature, 585(7825), p.E9 - E10, 2020/09
Pressure-induced structural transformations in deuterated crystalline ice-Ih were studied in-situ at 100 K using neutron diffraction. Very long relaxation time was allowed between small pressure increments to promote transformations to the thermodynamic stable high pressure crystalline phases. The results contradict a recent report in which measurements under similar temperature and pressure environment show successive crystal-to-crystal transformations (Tulk, et.al., Nature 2019). Instead, ice Ih was found to transform partially to an amorphous form (high density amorphous, HDA) at 1.0 GPa and then ice VII started to emerge at 1.5 GPa, a pressure substantially lower than all earlier studies. During this pressure interval, crystalline ice Ih or ice VII co-exist with HDA. The ice VII formed is stable upon pressure release down to 0.1 GPa. The very low compression rate has a profound effect on the crystallinity in the amorphous regime. Gathering all the existing experimental evidences allows an unambiguous description of the phenomenon of pressure induced amorphization. The onset of the phase transition is triggered by a shear instability of the ice lattice. The co-existence ice VII with HDA, instead of the equilibrium thermodynamic stable and proton-ordered ice-VIII under the same pressure-temperature condition reveals at low temperature there is insufficient thermal energy to overcome the substantial geometrical rearrangement from a single proton disordered H-bond network to an interpenetrating proton ordered H-bond crystalline network. Thus, leaving the proton disordered H-network intact. The analysis shows unequivocally that the structure obtained from the compression of ice is controlled by kinetics and dependent on the temperature.
Kikkawa, Takashi*; Shen, K.*; Flebus, B.*; Duine, R. A.*; Uchida, Kenichi*; Qiu, Z.*; Bauer, G. E. W.*; Saito, Eiji
Physical Review Letters, 117(20), p.207203_1 - 207203_6, 2016/11
Geprgs, S.*; Kehlberger, A.*; Coletta, F.*; Qiu, Z.*; Guo, E.-J.*; Schulz, T.*; Mix, C.*; Meyer, S.*; Kamra, A.*; Althammer, M.*; et al.
Nature Communications (Internet), 7, p.10452_1 - 10452_6, 2016/02
Bottoni, S.*; Leoni, S.*; Fornal, B.*; Raabe, R.*; Rusek, K.*; Benzoni, G.*; Bracco, A.*; Crespi, F. C. L.*; Morales, A. I.*; Bednarczyk, P.*; et al.
Physical Review C, 92(2), p.024322_1 - 024322_8, 2015/08
Schreier, M.*; Bauer, G. E. W.*; Vasyuchka, V.*; Flipse, J.*; Uchida, Kenichi*; Lotze, J.*; Lauer, V.*; Chumak, A.*; Serga, A.*; Daimon, Shunsuke*; et al.
Journal of Physics D; Applied Physics, 48(2), p.025001_1 - 025001_5, 2015/01
Sakai, Hironori; Urbano, R. R.*; Tokunaga, Yo; Kambe, Shinsaku; Suzuki, Michito; Kuhns, P. L.*; Reyes, A. P.*; Tobash, P. H.*; Ronning, F.*; Bauer, E. D.*; et al.
Physical Review Letters, 112(23), p.236401_1 - 236401_5, 2014/06
Very high field Si-NMR measurements using a fully Si-enriched URuSi single crystal were carried out in order to microscopically investigate the "hidden order" (HO) state and adjacent magnetic phases in the high field limit. At the lowest measured temperature of 0.4 K, a clear anomaly reflecting a Fermi surface instability near 22 T inside the HO state is detected by the Si shift, . Moreover, a strong enhancement of develops near a critical field T, and the Si-NMR signal disappears suddenly at , indicating the total suppression of the HO state. Nevertheless, a weak and shifted Si-NMR signal reappears for fields higher than at 4.2 K, providing evidence for a magnetic structure within the magnetic phase caused by the Ising-type anisotropy of the uranium ordered moments.
Illana, A.*; Jungclaus, A.*; Orlandi, R.; Perea, A.*; Bauer, C.*; Briz, J. A.*; Egido, J. L.*; Gernhuser, R.*; Leske, J.*; Mcher, D.*; et al.
Physical Review C, 89(5), p.054316_1 - 054316_11, 2014/05
Haga, Yoshinori; Bauer, E. D.*; Tobash, P. H.*; Mitchell, J. N.*; Ayala-Valenzuela, O.*; McDonald, R. D.*; Mielke, C. H.*; Fisk, Z.
Journal of the Korean Physical Society, 63(3), p.380 - 382, 2013/08
Althammer, M.*; Meyer, S.*; Nakayama, Hiroyasu*; Schreier, M.*; Altmannshofer, S.*; Weiler, M.*; Huebl, H.*; Geprgs, S.*; Opel, M.*; Gross, R.*; et al.
Physical Review B, 87(22), p.224401_1 - 224401_15, 2013/06
We experimentally investigate and quantitatively analyze the spin Hall magnetoresistance (SMR) effect in ferromagnetic insulator (FI)/Pt and FI/nonmagnetic metal/Pt hybrid structures. For the FI, we use either YIG, nickel ferrite, or magnetite and for the nonmagnet, Cu or Au. The SMR is theoretically ascribed to the combined action of spin Hall and inverse spin Hall effect in the Pt top layer. It therefore should characteristically depend upon the orientation of the magnetization in the adjacent ferromagnet and prevail even if an additional, nonmagnetic metal layer is inserted between Pt and the ferromagnet. Our experimental data corroborate these theoretical conjectures. Using the SMR theory to analyze our data, we extract the spin Hall angle and the spin diffusion length in Pt. For a spin-mixing conductance of m, we obtain a spin Hall angle of 0.11 0.08 and a spin diffusion length of (1.5 0.5) nm for Pt in our samples.
Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Baumbach, R. E.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
Physical Review B, 86(9), p.094402_1 - 094402_8, 2012/09
Nuclear magnetic resonance (NMR) studies using B and Ga have been performed on the tetragonal Ce-based ferromagnet CeRuGaB. The Knight shifts for the nuclei show an Ising-type anisotropy along the axis, similar to results from the static susceptibility. From the Knight shift measurements, the hyperfine coupling constants have been determined. The anisotropy of the spin- lattice relaxation rates indicates that the anisotropy of spin fluctuations are also Ising-like along the axis. The localized character of the electrons in this system is discussed.
Raumbach, R. E.*; Chudo, Hiroyuki; Yasuoka, Hiroshi; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
Physical Review B, 85(9), p.094422_1 - 094422_7, 2012/03
Fukano, Yoshitaka; Kawada, Kenichi; Sato, Ikken; Wright, A. E.*; Kilsdonk, D. J.*; Aeschlimann, R. W.*; Bauer, T. H.*
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles (FR 2009) (CD-ROM), 10 Pages, 2012/00
Wright, A. E.*; Bauer, T. H.*; Kilsdonk, D. J.*; Aeschlimann, R. W.*; Fukano, Yoshitaka; Kawada, Kenichi; Sato, Ikken
Proceedings of International Conference on Fast Reactors and Related Fuel Cycles (FR 2009) (CD-ROM), 9 Pages, 2012/00
Sakai, Hironori; Kurita, Nobuyuki*; Miclea, C. F.*; Movshovich, R.*; Lee, H.-O.*; Ronning, F.*; Bauer, E. D.*; Thompson, J. D.*
Journal of the Physical Society of Japan, 80(Suppl.A), p.SA059_1 - SA059_3, 2011/07
The effect of dilute La substitution in CeLaRhIn (0x0.07) has been investigated microscopically by nuclear magnetic/quadrupole resonance (NMR/NQR). By the dilute La substitutions, the 4 lines for In(1) sites are found to be undisturbed and to have a reasonably narrow width, even in the ordered AF state. These 4 positions in the La-substituted CeRhIn indicate a decrease of the internal field on In(1) sites, due to the reduction of hyperfine couplings by La substitutions. The spin-lattice relaxation rates () using these 4 lines at high temperatures can be understood by the reduction of exchange energy and effective moments. On the other hand, in the AF ordered state can be explained by a gapped Fermi surface and spin fluctuations of uncompensated localized Ce moments near the La ions.
Bauer, E. D.*; Yang, Y.-F.*; Capan, C.*; Urbano, R. R.*; Miclea, C. F.*; Sakai, Hironori; Ronning, F.*; Graf, M. J.*; Balatsky, A. V.*; Movshovich, R.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 108(17), p.6857 - 6861, 2011/04
Here, we report a manifestation of electronic inhomogeneity in a strongly correlated -electron system, using CeCoIn as an example. A thermodynamic analysis of its superconductivity, combined with nuclear quadrupole resonance measurements, shows that nonmagnetic impurities (Y, La, Yb, Th, Hg, and Sn) locally suppress unconventional superconductivity, generating an inhomogeneous electronic "Swiss cheese" due to disrupted periodicity of the Kondo lattice. Our analysis may be generalized to include related systems, suggesting that electronic inhomogeneity should be considered broadly in Kondo lattice materials.
Heffner, R.*; Goko, Tatsuo*; Andreica, D.*; Oishi, Kazuki*; Higemoto, Wataru; Ito, Takashi; Amato, A.*; Spehling, J.*; Klauss, H. H.*; Bauer, E. D.*; et al.
Journal of Physics; Conference Series, 225, p.012011_1 - 012011_6, 2010/06
Oishi, Kazuki; Heffner, R. H.; Ito, Takashi; Higemoto, Wataru; Morris, G. D.*; Bauer, E. D.*; Graf, M. J.*; Zhu, J.-X.*; Morales, L. A.*; Sarrao, J. L.*; et al.
Physica B; Condensed Matter, 403(5-9), p.1013 - 1014, 2008/04
PuCoGa has attracted much interest because it is the first Pu-based superconductor, having an order of magnitude higher transition temperature K than the isostructural heavy fermion superconductor CeCoIn (K). The mechanism of the superconductivity in PuCoGa is still under investigation, though recent experiments and theory suggest a magnetic origin. A unique aspect of this compound is the self-irradiation damage because Pu (Pu, = 24,000 years) creates lattice defects which scatter electrons and, hence, break superconducting pairs. In order to elucidate the magnitude and temperature dependence of the magnetic penetration depth , we have performed SR measurements in the same PuCoGa single crystals after 25 and 400 days of aging. We found that decreased from 18.5K to 15K for the aged sample, yet a quasi-linear temperature dependence was found for the low-temperature in both the fresh and aged sample, consistent with -wave pairing symmetry. The magnitude of the muon spin relaxation rate in the aged sample, , where and are the superfluid density and the effective mass, respectively, is reduced by about 70% compared to fresh sample. This indicates that the scattering from self-irradiation induced defects is not in the limit of the conventional Abrikosov-Gor'kov pair-breaking theory, but rather in the limit of short coherence length (about 2nm in PuCoGa) superconductivity.
Oishi, Kazuki; Heffner, R. H.; Ito, Takashi; Higemoto, Wataru; Morris, G. D.*; Hur, N.*; Bauer, E. D.*; Sarrao, J. L.*; Thompson, J. D.*; MacLaughlin, D. E.*; et al.
Journal of Physics and Chemistry of Solids, 68(11), p.2068 - 2071, 2007/11
no abstracts in English
Heffner, R. H.; Oishi, Kazuki; Fluss, M. J.*; Morris, G. D.*; MacLaughlin, D. E.*; Shu, L.*; Chung, B. W.*; McCall, S. K.*; Bauer, E. D.*; Sarrao, J. L.*; et al.
Journal of Alloys and Compounds, 444-445, p.80 - 83, 2007/10
We summarize the results of muon spin relaxation (SR) measurements carried out in- and -Pu and in the superconducting state ofPuCoGa. In Pu metal, interest has centered on whether or not magnetic order exists in the hightemperature fcc phase,The Pu metal studies were designed to search for evidence of magnetic ordering, andhave set the most stringent limits to date for the ordered moment. In PuCoGa the temperature dependence of themagnetic penetration depth (T) was investigated in a fresh sample and again in the same sampleafter 400 days of aging. We find (T) T for T Tc/2, indicating a line of nodes in thesuperconducting order parameter. Remarkably, the temperature dependence of (T) is littlechanged even after significant radiation damage.