Interstitial Doping Induced Superconductivity At 15.3 K In Nb 5ge 3 Compound

It is reported superconductivity in Nb 5Ge 3C 0.3, an interstitial carbide compound. The temperature dependence of the electrical resistivity, ac-susceptibility, and heat capacity (HC) indicate that a bulk type-II superconductivity appears at T C=15.3 K. Magneto-resistance measurements suggest an upper critical field of B C2 ∼ 10.6 T and a coherence length of ∈ ∼ 55 Å at zero temperature. Neutron diffraction analyzes locate the carbon atoms at the interstitial 2b site of the Mn 5Si 3 type-structure. Heat capacity data below T C are well described by BCS theory. The size of the jump at T C is in good agreement with the superconducting volume fraction observed in susceptibility measurements. A Debye temperature and Sommerfeld constant were also extracted from heat capacity data as 343 K and 34 mJ/mol K 2, respectively. © 2012 American Institute of Physics.11112Massalski, T.B., (1990) Binary Alloy Phase Diagrams, 100, p. 247002. , 2nd ed. (Materials Park, OH)Labb, J., Friedel, J.J., (1966) J. Phys., 27, p. 708. , 10.1051/jphys:019660027011-12070800Gor'Kov, L.P., (1973) Pis'Ma Zh. Eksp. Teor. Fiz., 17 (9), p. 525Nagamatsu, J., Nakagawa, N., Muranaka, T., Zenitani, Y., Akimitsu, J., (2001) Nature (London), 410, p. 6824. , 10.1038/35065039Ghosh, A.K., Douglass, D.H., (1976) Phys. Rev. Lett., 37, p. 32. , 10.1103/PhysRevLett.37.32Knoedler, C.M., Douglass, D.H., (1979) J. Low Temp. Phys., 37, p. 189. , 10.1007/BF00114067Remeika, J.P., Cooper, A.S., Fisk, Z., Johnston, D.C., (1978) J. Less-Common Met., 62, p. 211. , 10.1016/0022-5088(78)90033-4Claeson, T., Ivarsson, J., (1977) J. Appl. Phys., 48, p. 3998. , 10.1063/1.324239Spear, K.E., Palino, D.P., (1983) Mater. Res. Bull., 18, p. 549. , 10.1016/0025-5408(83)90212-XNowotny, H., Searcy, A.W., Orr, J.E., (1956) J. Am. Chem. Soc., 78, p. 677Jeitscko, W., Nowotny, H., Benesovsky, D., (1964) Mh. Chem., 95, p. 1242. , 10.1021/j150539a042Arita, M., Nissen, H.-U., Schauer, W., (1990) J. Sol. Stat. Chem., 84, p. 386. , (2), () 10.1016/0022-4596(90)90336-VKrauss, W., Nolse, G., (1996) J. Appl. Cryst., 29, p. 301. , 10.1107/S0021889895014920Villars, P., Calvert, L.D., (1991) Person's Handbook of Crystallographic Data for Intermetallic Phases, 3. , (The Materials Information Society)Rodriguez-Carvajal, J., (1990) Satellite Meeting on Powder Diffraction of the XV Congress of the IUCr, p. 127Woodard, D.W., Codey, G.D., (1964) Phys. Rev., 136, p. 166. , 10.1103/PhysRev.136.A166Hiroi, Z., Yonezawa, S., Nagao, Y., Yamaura, J., (2007) Phys. Rev. B, 76, p. 014523. , 10.1103/PhysRevB.76.014523Fisk, Z., Webb, G.W., (1976) Phys. Rev. Lett., 36, p. 1084. , 10.1103/PhysRevLett.36.1084Webb, G.W., Fisk, Z., Engelhardt, J.J., Bader, S.D., (1977) Phys. Rev. B, 15, p. 2624. , 10.1103/PhysRevB.15.2624Cohen, R.W., Cody, G.W., Halloran, J.J., (1967) Phys. Rev. Lett., 19, p. 840. , 10.1103/PhysRevLett.19.840Allen, P.B., (1971) Phys. Rev. B, 3, p. 305. , 10.1103/PhysRevB.3.305Regueiro, M.N., (1986) Solid State Commun., 60, p. 797. , 10.1016/0038-1098(86)90599-5Bortolozo, A.D., Dos Santos, C.A.M., Jardim, R.F., MacHado, A.J.S., (to be submitted)Dos Santos, C.A.M., Kopelevich, Y., Moehlecke, S., MacHado, A.J.S., (2003) Physica C, 390, p. 21. , 10.1016/S0921-4534(02)02802-2Stewart, G.R., Newkirk, L.R., Valencia, F.A., (1978) Solid State Commun., 26, p. 417. , 10.1016/0038-1098(78)90518-5Bruhwiler, M., Kazakov, S.M., Zhigadlo, N.D., Karpinski, J., Batlogg, B., (2004) Phys. Rev. B, 70, p. 020503. , 10.1103/PhysRevB.70.020503Kamark, J., Pribulov, Z., Marcenat, C., Klein, T., Rodire, P., Cario, L., Samuely, P., (2010) Phys. Rev. B, 82, p. 014518. , 10.1103/PhysRevB.82.014518Kohama, Y., Kim, S.W., Tojo, T., Kawaji, H., Atake, T., Matsuishi, S., Hosono, H., (2008) Phys. Rev. B, 77, p. 092505. , 10.1103/PhysRevB.77.092505McMillan, W.L., (1968) Phys. Rev., 167, p. 331. , 10.1103/PhysRev.167.331Fang, L., Wang, Y., Zou, P.Y., Tang, L., Xu, Z., Chen, H., Dong, C., Wen, H.H., (2005) Phys. Rev. B., 72, p. 014534. , 10.1103/PhysRevB.72.01453

Molecular characterization of Malassezia sympodialis and Malassezia furfur from cattle with and without otitis Caracterização molecular de isolados de Malassezia sympodialis e Malassezia furfur provenientes de bovinos com e sem otite externa

A molecular study of Malassezia strains isolated from cattle with or without otitis was carried out by random amplified polymorphic DNA analysis (RAPD). DNA was extracted and purified from nine strains of Malassezia sympodialis and fourteen of Malassezia furfur. These microorganisms were collected from eight different bovine herds in Minas Gerais state, Brazil. The RAPD analysis and phenograms did not show the formation of genetically distinct groups among the strain isolated from cattle with or without otitis raised in the same herds. Genetic heterogeneity was observed among Malassezia strains from different geographic origins. These data suggest that genetically similar M. sympodialis and M. furfur strains found as members of the normal ear microbiota could become opportunistically active in the inflammatory process in cattle.<br>A caracterização molecular de amostras de Malassezia spp., isoladas de bovinos com e sem otite, foi realizada por meio da técnica do DNA polimórfico amplificado ao acaso (RAPD). DNAs de nove amostras de Malassezia sympodialis e quatorze de M. furfur foram extraídos e purificados. Essas amostras foram provenientes de oito diferentes rebanhos bovinos no estado de Minas Gerais, Brasil. A análise de RAPD e os fenogramas não revelaram a formação de grupos geneticamente distintos entre amostras isoladas de bovinos, criados no mesmo rebanho, com ou sem otite. Heterogeneidade genética foi observada entre amostras de diferentes origens geográficas. Os dados sugerem que isolados geneticamente semelhantes e membros da microbiota normal do ouvido podem participar, como oportunistas, no processo inflamatório do conduto auditivo externo de bovinos