Superconductivity in the Layered Intergrowth Compound La3Ni4P4O2 (2008)
Klimczuk, T., McQueen, T. M., Williams, A. J., Huang, Q., Ronning, F., Bauer, E. D., ...
Superconductivity with a Tc of 2.2 K is reported for the previously unknown compound La3Ni4P4O2. This compound represents a new structure type for the oxypnictide superconductors. Heat capacity...
First order magnetic transition in single crystal CaFe$_2$As$_2$ detected by $^{75}$As NMR (2008)
Curro, N. J., Klimczuk, T., Bauer, E. D., Ronning, F., Thompson, J. D.
We report $^{75}$As Nuclear Magnetic Resonance data in a single crystal of CaFe$_2$As$_2$. The Knight shift, electric field gradient, and spin-lattice relaxation rate are strongly temperature...
First Order Phase Transition and Superconductivity in BaNi2As2 Single Crystals (2008)
Ronning, F., Kurita, N., Bauer, E. D., Scott, B. L., Park, T., Klimczuk, T., ...
We report the synthesis and physical properties of single crystals of stoichiometric BaNi2As2 that crystalizes in the ThCr2Si2 structure with lattice parameters a = 4.112(4) \AA and c = 11.54(2) \AA....
Klimczuk, T., Ronning, F., Bauer, E. D., Thompson, J. D., Curro, N. J.
We report an $^{75}$As NMR study of BaFe$_2$As$_2$ in both single crystals and polycrystal forms. We find that Sn impurities in the single crystal dramatically alter the low energy spin fluctuations...
Pressure-induced superconductivity in single crystal CaFe2As2 (2008)
Park, Tuson, Park, Eunsung, Lee, Hanoh, Klimczuk, T., Bauer, E D, Ronning, F, ...
We report pressure-induced superconductivity in a single crystal of CaFe2As2. At atmospheric pressure, this material is antiferromagnetic below 170 K but under an applied pressure of 0.69 GPa becomes...
Synthesis and Properties of CaFe$_2$As$_2$ Single Crystals (2008)
Ronning, F., Klimczuk, T., Bauer, E. D., Volz, H., Thompson, J. D.
We report the synthesis and basic physical properties of single crystals of CaFe2As2, an isostructural compound to BaFe2As2 which has been recently doped to produce superconductivity. CaFe2As2...
Physical properties of the new Uranium ternary compounds U3Bi4M3 (M=Ni, Rh) (2008)
Klimczuk, T., Lee, Han-oh, Ronning, F., Durakiewicz, T., Kurita, N., Volz, H., ...
We report the properties of two new isostructural compounds, U3Bi4Ni3 and U3Bi4Rh3. The first of these compounds is non-metallic, and the second is a nearly ferromagnetic metal, both as anticipated...
Magnetism and structure of LixCoO2 and comparison to NaxCoO2 (2007)
Hertz, J. T., Huang, Q., McQueen, T., Klimczuk, T., Bos, J. W. G., Viciu, L., ...
The magnetic properties and structure of LixCoO2 for x between 0.5 and 1.0 are reported. Co4+ is found to be high-spin in LixCoO2 for x between 0.94 and 1.0 and low-spin for x between 0.50 and 0.78....
Holman, K. L., Morosan, E., Casey, P. A., Li, Lu, Ong, N. P., Klimczuk, T., ...
Five compounds were investigated for magnetic character and superconductivity, all with non-magnetic nickel and band structures containing flat bands and steep bands. The syntheses and crystal...
Physical properties of the noncentrosymmetric superconductor Mg_10Ir_19B_16 (2007)
Klimczuk, T., Ronning, F., Sidorov, V., Cava, R. J., Thompson, J. D.
Specific heat, electrical resistivity, and magnetic susceptibility measurements on a high quality sample of Mg10Ir19B16 provide a self-consistent determination of its superconducting properties. They...
The effect of Fe and Ru substitution for Ni on the thermopower in MgCNi_3 (2007)
Sulkowski, C., Klimczuk, T., Cava, R. J., Rogacki, K.
The intermetallic perovskite MgCNi3 is a superconductor with a Tc=7 K. Substitution of Fe and Ru for Ni decreases Tc monotonically as the doping concentration is increased. Here we report thermopower...
Rich magnetic phase diagram in the Kagome-staircase compound Mn3V2O8 (2007)
Morosan, E., Fleitman, J., Klimczuk, T., Cava, R. J.
Mn3V2O8 is a magnetic system in which S = 5/2 Mn2+ is found in the kagome staircase lattice. Here we report the magnetic phase diagram for temperatures above 2 K and applied magnetic fields below 9...
McQueen, T. M., Huang, Q., Lynn, J. W., Berger, R. F., Klimczuk, T., Ueland, B. G., ...
The magnetic properties of $\alpha$-NaFeO$_2$ are studied by neutron diffraction and magnetization measurements. An ordered phase with spins aligned along the b$_hex$ axis exists at low temperatures...
Superconductivity in Mg10Ir19B16 (2006)
Klimczuk, T., Xu, Q., Morosan, E., Zandbergen, H. W., Cava, R. J.
Mg10Ir19B16, a previously unreported compound in the Mg-Ir-B chemical system, is found to be superconducting at temperatures near 5 K. The fact that the compound exhibits a range of superconducting...
Superconductivity in Cu_xTiSe_2 (2006)
Morosan, E., Zandbergen, H. W., Dennis, B. S., Bos, J. W. G., Onose, Y., Klimczuk, T., ...
Charge density waves (CDWs) are periodic modulations of the conduction electron density in solids. They are collective states that arise from intrinsic instabilities often present in low dimensional...
Influence of conditions of synthesis on superconductivity in Nd2-xCexCuO4-y. (2006)
Plebanczyk, M., Klimczuk, T., Gortenmulder, T.J., Fiertek, P., Sadowski, W.
Ca_25Co_22O_56(OH)_28: a layered misfit compound (2005)
Klimczuk, T., Zandbergen, H. W., Van Der Pers, N. M., Viciu, L., Miller, V. L., ...
The high pressure synthesis, structure and magnetic properties of Ca_25Co_22O_56(OH)_28 are reported. The compound has a misfit structure, consisting of double, square calcium oxide hydroxide...
Nanometer structural columns and frustration of magnetic ordering in Nb12O29 (2005)
Andersen, E.N., Klimczuk, T., Miller, V.L., Zandbergen, H.W., Cava, R.J.
The effect of {11}^B substitution on the superconductivity in MgCNi3 (2004)
Klimczuk, T., Avdeev, M., Jorgensen, J. D., Cava, R. J.
The crystal structure of boron doped superconducting MgC_{1-x}{11}^B_{x}Ni_{3}, studied by powder neutron diffraction, is reported. The solubility limit of boron is determined to be approximately...
Hydration phase diagram for sodium cobalt oxide Na0.3CoO2*yH2O (2004)
Foo, M. L., Klimczuk, T., Cava, R. J.
The hydration phase diagram for sodium cobalt oxyhydrate, Na0.3CoO2*yH2O (y=0, 0.6, 1.3), was determined as a function of relative humidity at 298K. It is found that greater than 75% relative...
Carbon isotope effect in superconducting MgCNi_3 (2004)
The effect of Carbon isotope substitution on T_c in the intermetallic perovskite superconductor MgCNi_3 is reported. Four independent groups of samples were synthesized and characterized. The average...
Superconductivity in three-layer Na0.3CoO2*1.3H2O (2004)
Foo, M. L., Klimczuk, T., Li, Lu, Ong, N. P., Cava, R. J.
The observation of superconductivity at 4.3 K in a new crystalline form of Na0.3CoO2*1.3H2O is reported. The new superconductor has three layers of CoO6 octahedra per crystallographic unit cell, in...
The Effect of Ru substitution for Ni on the superconductivity in MgCNi3-xRux (2004)
Klimczuk, T., Gupta, V., Lawes, G., Ramirez, A. P., Cava, R. J.
The superconductor MgCNi3 has been chemically doped by partial substitution of Ru for Ni in the solid solution MgCNi3-xRux for 0
Possible singlet to triplet pairing transition in NaxCoO2 H2O (2004)
Maska, M. M., Mierzejewski, M., Andrzejewski, B., Foo, M. L., Cava, R. J., Klimczuk, T.
We present precise measurements of the upper critical field (Hc2) in the recently discovered cobalt oxide superconductor. We have found that the critical field has an unusual temperature dependence;...
Superconductivity Phase Diagram of Na(x)CoO(2).1.3H(2)O (2003)
Schaak, R. E., Klimczuk, T., Foo, M. L., Cava, R. J.
Although the microscopic origin of the superconductivity in high Tc copper oxides remains the subject of active inquiry, several of their electronic characteristics are well established as universal...
Chemical Instability of the Cobalt Oxyhydrate Superconductor under Ambient Conditions (2003)
Foo, M. L., Schaak, R. E., Miller, V. L., Klimczuk, T., Rogado, N. S., Wang, Yayu, ...
The layered sodium cobalt oxyhydrate superconductor Na0.3CoO2*1.4H2O is shown through X-ray diffraction and thermogravimetric studies to be one of a series of hydrated phases of Na0.3CoO2. Further,...