K. Conder

Publication List Details

Period

1997 - 2008

Number

41

Co-Authors

Muon-spin rotation study of the in-plane magnetic penetration depth of FeSe_0.85: evidence for nodeless superconductivity (2008)

Khasanov, R., Conder, K., Pomjakushina, E., Amato, A., Baines, C., Bukowski, Z., ...

The in-plane magnetic penetration depth \lambda_{ab} of the iron selenide superconductor with the nominal composition FeSe_0.85 was studied by means of muon-spin rotation. The measurements of...

Magnetic and electronic Co states in layered cobaltate GdBaCo2O5.5-x (2008)

Garcia-Fernandez, M., Scagnoli, V., Staub, U., Mulders, A. M., Janousch, M., Bodenthin, Y., ...

We have performed non-resonant x-ray diffraction, resonant soft and hard x-ray magnetic diffraction, soft x-ray absorption and x-ray magnetic circular dichroism measurements to clarify the electronic...

Microscopic Evidence of Spin State Order and Spin State Phase Separation in Layered Cobaltites RBaCo2O5.5 with R=Y, Tb, Dy, and Ho (2008)

Luetkens, H., Stingaciu, M., Pashkevich, Yu. G., Conder, K., Pomjakushina, E., Gusev, A. A., ...

We report muon spin relaxation measurements on the magnetic structures of RBaCo_2O_5.5 with R=Y, Tb, Dy, and Ho. Three different phases, one ferrimagnetic and two antiferromagnetic, are identified...

Spin-state polaron in lightly hole-doped LaCoO_3 (2008)

Podlesnyak, A., Russina, M., Furrer, A., Alfonsov, A., Vavilova, E., Kataev, V., ...

Inelastic neutron scattering (INS), electron spin (ESR) and nuclear magnetic resonance (NMR) measurements were employed to establish the origin of the strong magnetic signal in lightly hole-doped...

A Resonant soft x-ray powder diffraction study to determine the orbital ordering in A-site ordered SmBaMn2O6 (2008)

Garcia-Fernandez, M., Staub, U., Bodenthin, Y., Lawrence, S. M., Mulders, A. M., Buckley, C. E., ...

Soft X-ray resonant powder diffraction has been performed at the Mn L2,3 edges of A-site ordered SmBaMn2O6. The energy and polarization dependence of the (1/2 1/2 0) reflection provide direct...

Oxygen isotope effect on superconductivity and magnetism in Y_1-xPr_xBa_2Cu_3O_7-\delta (2007)

Khasanov, R., Shengelaya, A., Di Castro, D., Morenzoni, E., Maisuradze, A., Savić, I. M., ...

Oxygen isotope (^{16}O/^{18}O) effects (OIE's) on the superconducting transition (T_c), the spin-glass ordering (T_g), and the antiferromagnetic ordering (T_N) temperatures were studied for...

Oxygen-isotope effect on the superconducting gap in the cuprate superconductor Y_{1-x}Pr_xBa_2Cu_3O_{7-\delta} (2007)

Khasanov, R., Strässle, S., Conder, K., Pomjakushina, E., Bussmann-Holder, A., Keller, H.

The oxygen-isotope (^{16}O/^{18}O) effect (OIE) on the zero-temperature superconducting energy gap \Delta_0 was studied for a series of Y_{1-x}Pr_xBa_2Cu_3O_{7-\delta} samples (0.0\leq x\leq0.45)....

Crystal and magnetic structures of the spin-trimer compounds Ca3 Cu3xNix (PO4)4 (x=0,1,2) (2007)

Pomjakushin, V. Yu., Furrer, A., Sheptyakov, D. V., Pomjakushina, E. V., Conder, K.

Crystal and magnetic structures of a series of novel quantum spin trimer system Ca3Cu3xNix(PO4)4 (x=0,1,2) were studied by neutron powder diffraction at the temperatures 1.5-290 K. The composition...

Magnetic excitations in the spin-trimer compounds Ca3Cu3-xNix(PO4)4 (x=0,1,2) (2007)

Podlesnyak, A., Pomjakushin, V., Pomjakushina, E., Conder, K., Furrer, A.

Inelastic neutron scattering experiments were performed for the spin-trimer compounds Ca3Cu3-xNix(PO4)4 (x=0,1,2) in order to study the dynamic magnetic properties. The observed excitations can be...

Spontaneous ferromagnetic spin ordering at the surface of La$_2$CuO$_4$ (2007)

Yusupov, R. V., Kabanov, V. V., Mihailovic, D., Conder, K., Mueller, K. A., Keller, H.

Magnetic properties of high purity stoichiometric La$_2$CuO$_4$ nanoparticles are systematically investigated as a function of particle size. Ferromagnetic single-domain spin clusters are shown to...

Effect of oxygen isotope substitution and crystal micro-structure on magnetic ordering and phase separation in {$\rm (La_{1-y}Pr_{y})_{0.7}Ca_{0.3}MnO_3$} (2007)

Pomjakushin, V. Yu., Sheptyakov, D. V., Conder, K., Pomjakushina, E. V., Balagurov, A. M.

The crystal and magnetic structures of the specified CMR manganite system have been studied as a function of $y=(0.2-1)$ across the metal-insulator (MI) transition, and of the oxygen mass ($^{16}$O,...

Magnetic field dependence of the oxygen isotope effect on the magnetic penetration depth in hole-doped cuprate superconductors (2006)

Khasanov, R., Shengelaya, A., Di Castro, D, Eshchenko, D. G., Savich, I. M., Conder, K., ...

The magnetic field dependence of the oxygen-isotope (^{16}O/^{18}O) effect (OIE) on the in-plane magnetic field penetration depth \lambda_{ab} was studied in the hole-doped high-temperature cuprate...

Magnetism in Geometrically Frustrated YMnO3 Under Hydrostatic Pressure Studied with Implanted Muons (2006)

Lancaster, T., Blundell, S. J., Andreica, D., Janoschek, M., Roessli, B., Gvasaliya, S. N., ...

The rare-earth ferroelectromagnet YMnO3 consists of weakly coupled triangular layers of S=2 spins. Below T_N ~ 70 K muon-spin relaxation data show two oscillatory relaxing signals due to magnetic...

Effect of light Sr doping on the spin-state transition in LaCoO_3 (2006)

Podlesnyak, A., Conder, K., Pomjakushina, E., Mirmelstein, A., Allenspach, P., Khomskii, D. I.

We present an inelastic neutron scattering study of the low energy crystal-field excitations in the lightly doped cobalt perovskite La_0.998Sr_0.002CoO_3. In contrast to the parent compound LaCoO_3...

Correlation between oxygen isotope effects on the transition temperature and the magnetic penetration depth in high-temperature superconductors close to optimal doping (2006)

Khasanov, R., Shengelaya, A., Conder, K., Morenzoni, E., Savić, I. M., Karpinski, J., ...

The oxygen-isotope (^{16}O/^{18}O) effect (OIE) on the in-plane magnetic penetration depth \lambda_{ab}(0) in optimally-doped YBa_2Cu_3O_{7-\delta} and La_{1.85}Sr_{0.15}CuO_4, and in slightly...

Reduction of the ordered magnetic moment in YMnO3 with hydrostatic pressure (2005)

Janoschek, M., Roessli, B., Keller, L., Gvasaliya, S. N., Conder, K., Pomjakushina, E.

YMnO3 exhibits a ferroelectric transition at high temperature (~ 900 K) and magnetic ordering at T_N ~ 70 K where the dielectric constant shows an anomaly indicative of the magneto-dielectric effect....

Spin-state transition in LaCoO3: direct neutron spectroscopic evidence of excited magnetic states (2005)

Podlesnyak, A., Streule, S., Mesot, J., Medarde, M., Pomjakushina, E., Conder, K., ...

A gradual spin-state transition occurs in LaCoO3 around T~80-120 K, whose detailed nature remains controversial. We studied this transition by means of inelastic neutron scattering (INS), and found...

Spin fluctuations in the stacked-triangular antiferromagnet YMnO3 (2005)

Roessli, B., Gvasaliya, S. N., Pomjakushina, E., Conder, K.

The spectrum of spin fluctuations in the stacked-triangular antiferromagnet YMnO3 was studied above the Neel temperature using both unpolarized and polarized inelastic neutron scattering. We find an...

Evidence for charged critical fluctuations in underdoped Y-123 (2004)

Schneider, T., Khasanov, R., Conder, K., Pomjakushina, E., Bruetsch, R., Keller, H.

We report and analyze in-plane penetration depth measurements in YBa2Cu3O7-x taken close to the critical temperature Tc. In underdoped YBa2Cu3O6:59 we find consistent evidence for charged critical...

Oxygen-isotope effect on the in-plane penetration depth in cuprate superconductors (2004)

Khasanov, R., Shengelaya, A., Morenzoni, E., Conder, K., Savić, I. M., Keller, H.

Muon-spin rotation (muSR) studies of the oxygen isotope (^{16}O/^{18}O) effect (OIE) on the in-plane magnetic field penetration depth lambda_{ab} in cuprate high-temperature superconductors (HTS) are...

A metallic phase in lightly doped La$_{2-x}$Sr$_{x}$CuO$_{4}$ observed by electron paramagnetic resonance (2003)

Shengelaya, A., Bruun, M., Kochelaev, B. I., Safina, A., Conder, K., Muller, K. A.

In the low doping range of $x$ from 0.01 to 0.06 in La$_{2-x}$Sr$_{x}$CuO$_{4}$, a narrow electron paramagnetic resonance (EPR) line has been investigated. This line is distinct from the known broad...

Site-selective oxygen isotope effect on the magnetic field penetration depth in underdoped Y$_{0.6}$Pr$_{0.4}$Ba$_2$Cu$_3$O$_{7-\delta}$ (2003)

Khasanov, R., Shengelaya, A., Morenzoni, E., Angst, M., Conder, K., Savić, I. M., ...

We report site-selective oxygen isotope ($^{16}$O/$^{18}$O) effect (OIE) measurements on the in-plane penetration depth $\lambda_{ab} $ in underdoped Y$_{0.6}$Pr$_{0.4}$Ba$_2$Cu$_3$O$_{7-\delta}$,...

Absence of a boron isotope effect in the magnetic penetration depth of MgB$_{2}$ (2003)

Di Castro, D., Angst, M., Eshchenko, D. G., Khasanov, R., Roos, J., Savić, I. M., ...

The magnetic penetration depth $\lambda(0)$ in polycrystalline MgB$_{2}$ for different boron isotopes ($^{10}$B/$^{11}$B) was investigated by transverse field muon spin rotation. No boron isotope...

Direct observation of the oxygen isotope effect on the in-plane magnetic field penetration depth in optimally doped YBa$_2$Cu$_3$O$_{7-\delta}$ (2003)

Khasanov, R., Eshchenko, D. G., Luetkens, H., Morenzoni, E., Prokscha, T., Suter, A., ...

We report the first direct observation of the oxygen-isotope ($^{16}$O/$^{18}$O) effect on the in-plane penetration depth $\lambda_{ab}$ in a nearly optimally doped YBa$_2$Cu$_3$O$_{7-\delta}$ film...

Relevance of electron-lattice coupling in cuprates superconductors (2003)

Schneider, T., Khasanov, R., Conder, K., Keller, H.

We study the oxygen isotope (^{16}O,^{18}O) and finite size effects in Y_{1-x}Pr_{x}Ba_{2}Cu_{3}O_{7-\delta} by in-plane penetration depth (\lambda _{ab}) measurements. A significant change of the...

Unconventional isotope effects in the high-temperature cuprate superconductors (2002)

Zhao, Guo-meng, Keller, H., Conder, K.

We review various isotope effects in the high-T_c cuprate superconductors to assess the role of the electron-phonon interaction in the basic physics of these materials. Of particular interest are the...

Direct evidence for an intrinsic square vortex lattice in the overdoped high-Tc superconductor La1.83Sr0.17CuO4+d (2002)

Gilardi, R., Mesot, J., Drew, A., Divakar, U., Lee, S. L., Forgan, E. M., ...

We report here the first direct observations of a well ordered vortex lattice in the bulk of a La(2-x)Sr(x)CuO(4+d) (La214) single crystal (slightly overdoped, x=0.17). Our small angle neutron...

Oxygen-isotope effect on the in-plane penetration depth in underdoped Y_{1-x}Pr_xBa_2Cu_3O_{7-delta} as revealed by muon-spin rotation (2002)

Khasanov, R., Shengelaya, A., Conder, K., Morenzoni, E., Savić, I. M., Keller, H.

The oxygen-isotope (^16O/^18O) effect (OIE) on the in-plane penetration depth $\lambda_{ab} (0)$ in underdoped Y_{1-x}Pr_xBa_2Cu_3O_{7-delta} was studied by muon-spin rotation. A pronounced OIE on...

Oxygen Isotope Effect of the Plane-Copper NQR Frequency in YBa_2Cu_4O_8 (2001)

Mali, M., Roos, J., Keller, H., Karpinski, J., Conder, K.

We report on high-precision measurements of the temperature dependence of the plane-^63Cu NQR line frequency nu_Q(Cu2) and the linewidth in normal and superconducting ^16O and ^18O exchanged...

^25Mg NMR study of the MgB_2 superconductor (2001)

Mali, M., Roos, J., Shengelaya, A., Keller, H., Conder, K.

^25Mg NMR spectra and nuclear spin-lattice relaxation time, T_1, have been measured in polycrystalline ^25MgB_2 with a superconducting transition temperature T_c = 39.0 K in zero magnetic field. From...

Hole distribution for (Sr,Ca,Y,La)_14 Cu_24 O_41 ladder compounds studied by x-ray absorption spectroscopy (2000)

Nücker, N., Merz, M., Kuntscher, C. A., Gerhold, S., Schuppler, S., Neudert, R., ...

The unoccupied electronic structure for the Sr_14Cu_24O_41 family of two-leg ladder compounds was investigated for different partial substitutions of Sr^2+ by Ca^2+, leaving the nominal hole count...

Large oxygen-isotope effect in Sr_{0.4}K_{0.6}BiO_{3}: Evidence for phonon-mediated superconductivity (2000)

Zhao, Guo-meng, Conder, K., Angst, M., Kazakov, S. M., Karpinski, J., Maciejewski, M., ...

Oxygen-isotope effect has been investigated in a recently discovered superconductor Sr_{0.4}K_{0.6}BiO_{3}. This compound has a distorted perovskite structure and becomes superconducting at about 12...

Argon annealing of the oxygen-isotope exchanged manganite La_{0.8}Ca_{0.2}MnO_{3+y} (2000)

Zhao, G. M., Conder, K., Keller, H., Muller, K. A.

We have resolved a controversial issue concerning the oxygen-isotope shift of the ferromagnetic transition temperature T_{C} in the manganite La_{0.8}Ca_{0.2}MnO_{3+y}. We show that the giant...

Oxygen isotope effect on the in-plane penetration depth in underdoped La_{2-x}Sr_{x}CuO_{4} single crystals (1999)

Hofer, J., Conder, K., Sasagawa, T., Zhao, Guo-meng, Willemin, M., Keller, H., ...

We report measurements of the oxygen isotope effect (OIE) on the in-plane penetration depth \lambda_{ab}(0) in underdoped La_{2-x}Sr_{x}CuO_{4} single crystals. A highly sensitive magnetic torque...

Torque magnetometry on single-crystal high temperature superconductors near the critical temperature: a scaling approach (1999)

Hofer, J., Schneider, T., Singer, J. M., Willemin, M., Keller, H., Sasagawa, T., ...

Angular-dependent magnetic torque measurements performed near the critical temperature on single crystals of HgBa_{2}CuO_{4+y}, La_{2-x}Sr{x}CuO_{4}, and YBa_{2}Cu_{3}O_{6.93} are scaled, following...

Huge oxygen isotope effect on local lattice fluctuations in La(2-x)Sr(x)CuO(4) superconductor (1998)

Lanzara, A., Saini, N. L., Bianconi, A., Zhao, Guo-meng, Conder, K., Keller, H., ...

Recently a growing number of experiments have provided indications of the key role of polarons (composite particles formed by a charge strongly coupled with a local lattice deformation) in doped...

The dimpling in the CuO_2 planes of YBa_2Cu_3O_x (x=6.806-6.984, T=20-300 K) measured by yttrium EXAFS (1997)

Röhler, J., Link, S., Conder, K., Kaldis, E.

The dimpling of the CuO_2 planes (spacing between the O2,3 and Cu2 layers) in YBa_2Cu_3O_x has been measured as a function of oxygen concentration and temperature by yttrium x-ray...

A Displacive Structural Transformation in the CuO_2 Planes of YBa_2Cu_3O_x at the Underdoped-Overdoped Phase Separation Line (1997)

Kaldis, E., Röhler, J., Liarokapis, E., Poulakis, N., Conder, K., Loeffen, P. W.

A structural phase transformation in the CuO_2 planes of YBa_2Cu_3O_x has been observed at the onset of the overdoped regime, x=6.95. We have measured as a function of x the dimpling in the CuO_2...

Local structure studies of the underdoped-overdoped transition in YBa_2Cu_3O_x. Measurement of the yttrium y-ray absorption fine structure (1997)

Röhler, J., Loeffen, P. W., Müllender, S., Conder, K., Kaldis, E.

We have measured the extended x-ray absorption-fine-structure (EXAFS) at the Y-K edge of YBa_2Cu_3O_x for x=6.801, 6.947, 6.968, 6.984 at T=20-300 K. Across the underdoped-overdoped transition the...