Publications (73)
Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. III. Constraints from a subgiant
K. Brogaard, F. Grundahl, E. L. Sandquist +18
Models of stellar structure and evolution can be constrained using accurate measurements of the parameters of eclipsing binary members of open clusters. Multiple binary stars provi…
Magnetic order near 270 K in mineral and synthetic MnFeSbO ilmenite
R. Mathieu, S. A. Ivanov, G. V. Bazuev +4
The structural and magnetic properties of MnFeSbO single-crystalline mineral and ceramic samples synthesized under thermobaric treatment have been investigated, and compare…
The K2 M67 Study: Revisiting old friends with K2 reveals oscillating red giants in the open cluster M67
D. Stello, A. Vanderburg, L. Casagrande +6
Observations of stellar clusters have had a tremendous impact in forming our understanding of stellar evolution. The open cluster M67 has a particularly important role as a calibra…
Structural and magnetic properties of the ordered perovskite Pb2CoTeO6
S. A. Ivanov, P. Nordblad, R. Mathieu +2
The complex perovskite Pb2CoTeO6 (PCTO) has been prepared as polycrystalline powders by solid state reaction route, and the crystal structure and magnetic properties have been inve…
Spin Glasses: A Ghost Story
P. E. Jönsson, R. Mathieu, P. Nordblad +3
Extensive experimental and numerical studies of the non-equilibrium dynamics of spin glasses subjected to temperature or bond perturbations have been performed to investigate chaos…
Complex magnetism and magnetic field-driven electrical polarization in CoTeO
M. Hudl, R. Mathieu, S. A. Ivanov +8
The magnetic and electrical properties of CoTeO single-crystals with corundum related structure reveal a magnetic-field induced polarization below 21 K. A sharp peak in the…
Effect of antiferromagnetic spin correlations on lattice distortion and charge ordering in PrCaMnO
Songxue Chi, F. Ye, Pengcheng Dai +7
We use neutron scattering to study the lattice and magnetic structure of the layered half-doped manganite PrCaMnO. On cooling from high temperature, the system…
Influence of the cation on the low-temperature antiferromagnetism of ordered antiferroelectric CoTeO perovskites
R. Mathieu, S. A. Ivanov, R. Tellgren +1
We have investigated the structural and magnetic properties of antiferroelectric CoTeO perovskites with = Cd, Ca, Sr, Pb, and Ba. All compounds are antiferromagnetic a…
Grain boundary effects on magnetotransport in bi-epitaxial films of LaSrMnO
R. Mathieu, P. Svedlindh, R. A. Chakalov +1
The low field magnetotransport of LaSrMnO (LSMO) films grown on SrTiO substrates has been investigated. A high qualtity LSMO film exhibits anisotropic magne…
Effect of annealing on carrier density and Curie temperature in epitaxial (Ga,Mn)As thin films
B. Sorensen, J. Sadowski, R. Mathieu +2
We report a clear correspondence between changes in the Curie temperature and carrier density upon annealing in epitaxially grown (Ga,Mn)As layers with thicknesses in the range bet…
MnFeSbO: a ferrimagnetic ilmenite and an antiferromagnetic perovskite
R. Mathieu, S. A. Ivanov, I. V. Solovyev +4
Due of its polymorphism, MnFeSbO can be synthesized at high pressures and temperatures as a ferrimagnetic ilmenite or an antiferromagnetic perovskite. The structural phase…
Ferromagnetic GaMnAs/GaAs superlattices - MBE growth and magnetic properties
J. Sadowski, R. Mathieu, P. Svedlindh +9
We have studied the magnetic properties of (GaMnAs)m/(GaAs)n superlattices with magnetic GaMnAs layers of thickness between 8 and 16 molecular layers (ML) (23-45 Ã ), and with nonm…
Short-range spin order and frustrated magnetism in Mn2InSbO6 and Mn2ScSbO6
S. A. Ivanov, P. Nordblad, R. Mathieu +3
The complex metal oxides Mn2ASbO6 (A=In, Sc) with a corundum-related structure A3BO6 have been prepared as polycrystalline powders by a solid state reaction route. The crystal stru…
Mott versus Slater-type metal-insulator transition in Mn-substituted Sr3Ru2O7
M. A. Hossain, B. Bohnenbuck, Y. D. Chuang +15
We present a temperature-dependent x-ray absorption (XAS) and resonant elastic x-ray scattering (REXS) study of the metal-insulator transition (MIT) in Sr3(Ru1-xMnx)2O7. The XAS re…
Electronic superlattice revealed by resonant scattering from random impurities in Sr3Ru2O7
M. A. Hossain, I. Zegkinoglou, Y. -D. Chuang +16
Resonant elastic x-ray scattering (REXS) is an exquisite element-sensitive tool for the study of subtle charge, orbital, and spin superlattice orders driven by the valence electron…
Logarithmic growth law in the two-dimensional Ising spin glass state resulting from the electron doping in single-layered manganites
R. Mathieu, J. P. He, Y. Kaneko +3
The ac-susceptibility of the electron doped single-layered manganite LaSrMnO is analyzed in detail. A quasi two-dimensional (2) antiferromagnetic (AFM) order…
The blue straggler V106 in NGC6791: A prototype progenitor of old single giants masquerading as young
K. Brogaard, S. M. Christiansen, F. Grundahl +18
We determine the properties of the binary star V106 in the old open cluster NGC6791. We identify the system to be a blue straggler cluster member by using a combination of ground-b…
Short range ferromagnetism and spin glass state in
R. Mathieu, P. Nordblad, D. N. H. Nam +2
Dynamic magnetic properties of are reported. The system appears to attain local ferromagnetic order at K. Below this…
Switching magnetic spin-states using small magnetic fields in compositionally complex Sm(M7)O
R. K. Dokala, M. Geers, P. Nordblad +2
High-entropy perovskites (HEPs) offer a unique platform for exploring magnetic phenomena arising from extreme B-site chemical disorder. In Sm(M7)O, where there are 7 cations in…
Photoemission studies of the annealing induced modifications of (Ga,Mn)As
M. Adell, L. Ilver, J. Kanski +2
Using angle resolved photoemission we have investigated annealing-induced changes in Ga(1-x)Mn(x)As with x = 0.05. We find that the position of the Fermi energy is a function of an…
Absence of Conventional Spin-Glass Transition in the Ising Dipolar System LiHo_xY_{1-x}F_4
P. E. Jönsson, R. Mathieu, W. Wernsdorfer +2
The magnetic properties of single crystals of LiHo_xY_{1-x}F_4 with x=16.5% and x=4.5% were recorded down to 35 mK using a micro-SQUID magnetometer. While this system is considered…
Spatially controlled formation of superparamagnetic (Mn,Ga)As nanocrystals in high temperature annealed (Ga,Mn)As/GaAs superlattices
J. Sadowski, J. Z. Domagala, R. Mathieu +2
The annealing-induced formation of (Mn,Ga)As nanocrystals in (Ga,Mn)As/GaAs superlattices was studied by X-ray diffraction, transmission electron microscopy and magnetometry. The s…
Spin and Dipole Ordering in Ni_2InSbO_6 and Ni_2ScSbO_6 with corundum-related structure
S. A. Ivanov, R. Mathieu, P. Nordblad +7
The complex metal oxides Ni2InSbO6 (NISO) and Ni2ScSbO6 (NSSO) have been prepared in form of polycrystalline powders by a solid state reaction route. The crystal structure and magn…
A prototype liquid Argon Time Projection Chamber for the study of UV laser multi-photonic ionization
B. Rossi, I. Badhress, A. Ereditato +15
This paper describes the design, realization and operation of a prototype liquid Argon Time Projection Chamber (LAr TPC) detector dedicated to the development of a novel online mon…
EuSrMnO: a three-dimensional XY spin glass
R. Mathieu, A. Asamitsu, Y. Kaneko +2
The frequency, temperature, and dc-bias dependence of the ac-susceptibility of a high quality single crystal of the EuSrMnO layered manganite is investigated. E…
Bandwidth-disorder phase diagram of half doped layered manganites
R. Mathieu, M. Uchida, Y. Kaneko +8
Phase diagrams in the plane of (the average ionic radius, related to one-electron bandwidth ) and (the ionic radius variance, measuring the quenched disorder), or `…
Phase transition in a super superspin glass
R. Mathieu, J. A. De Toro, D. Salazar +3
We here confirm the occurrence of spin glass phase transition and extract estimates of associated critical exponents of a highly monodisperse and densely compacted system of bare m…
The nanoscale phase separation in hole-doped manganites
R. Mathieu, Y. Tokura
A macroscopic phase separation, in which ferromagnetic clusters are observed in an insulating matrix, is sometimes observed, and believed to be essential to the colossal magnetores…
Temperature evolution of structural and magnetic properties of stoichiometric LiCu2O2: correlation of thermal expansion coefficient and magnetic order
S. A. Ivanov, P. Anil Kumar, R. Mathieu +3
Temperature-dependent crystallographic and magnetic studies on stoichiometric single crystals of LiCu2O2 are reported. The magnetic properties are similar to earlier findings demon…
Ferromagnetism and interlayer exchange coupling in short period (Ga,Mn)As/GaAs superlattices
R. Mathieu, P. Svedlindh, J. Sadowski +4
Magnetic properties of (Ga,Mn)As/GaAs superlattices are investigated. The structures contain magnetic (Ga,Mn)As layers, separated by thin layers of non-magnetic GaAs spacer. The sh…
New type of incommensurate magnetic ordering in Mn3TeO6
S. A. Ivanov, P. Nordblad, R. Mathieu +5
The complex metal oxide Mn3TeO6 exhibits a corundum related structure and has been prepared both in forms of single crystals by chemical transport reactions and of polycrystalline…
Strong rejuvenation in a chiral-glass superconductor
A. Gardchareon, R. Mathieu, P. E. Jönsson +1
The glassy paramagnetic Meissner phase of a BiSrCaCuO superconductor ( = 8.18) is investigated by squid magnetometry, using ``dc-memory'' experiments employed ea…
High-temperature structural phase transition in multiferroic LiCu_2O_2
S. A. Ivanov, A. A. Bush, K. E. Kamentsev +4
LiCu_2O_2 single crystals were studied in the temperature range 300-1100 K by means of heating-cooling curves of differential thermal analysis (DTA), thermogravimetry (TG), X-ray p…
Fe/V and Fe/Co (001) superlattices: growth, anisotropy, magnetisation and magnetoresistance
P. Nordblad, A. Broddefalk, R. Mathieu +3
Some physical properties of bcc Fe/V and Fe/Co (001) superlattices are reviewed. The dependence of the magnetic anisotropy on the in-plane strain introduced by the lattice mismatch…
Interlayer exchange coupling and giant magnetoresistance in Fe/V (001) superlattices
A. Broddefalk, R. Mathieu, P. Nordblad +4
Magnetization and magnetoresistivity studies of Fe/V (001) superlattices are reported. The first giant magnetoresistance peak with respect to the vanadium and iron layer thicknesse…
Cooling rate dependence of the antiferromagnetic domain structure of a single crystalline charge ordered manganite
R. Mathieu, P. Nordblad, A. R. Raju +1
The low temperature phase of single crystals of NdCaMnO and GdCaMnO manganites is investigated by squid magnetometry. NdCaMn…
Memory and chaos in an Ising spin glass
R. Mathieu, P. E. Jönsson, P. Nordblad +2
The non-equilibrium dynamics of the model 3d-Ising spin glass - FeMnTiO - has been investigated from the temperature and time dependence of the zero field coo…
Crystal-field level inversion in lightly Mn-doped Sr3Ru2O7
M. A. Hossain, Z. Hu, M. W. Haverkort +17
Sr3(Ru1-xMnx)2O7, in which 4d-Ru is substituted by the more localized 3d-Mn, is studied by x-ray dichroism and spin-resolved density functional theory. We find that Mn impurities d…
Coexistence of long-ranged charge and orbital order and spin-glass state in single-layered manganites with weak quenched disorder
R. Mathieu, J. P. He, X. Z. Yu +6
The relationship between orbital and spin degrees of freedom in the single-crystals of the hole-doped PrCaMnO, 0.3 0.7, has been investigated…
Magnetic Superstructure and Metal-Insulator Transition in Mn-Substituted Sr3Ru2O7
M. A. Hossain, B. Bohnenbuck, Y. -D. Chuang +18
We present a temperature-dependent resonant elastic soft x-ray scattering (REXS) study of the metal-insulator transition in Sr3(Ru1-xMnx)2O7, performed at both Ru and Mn L-edges. R…
Tuning of dielectric properties and magnetism of SrTiO3 by site-specific doping of Mn
D. Choudhury, S. Mukherjee, P. Mandal +12
Combining experiments with first principles calculations, we show that site-specific doping of Mn into SrTiO3 has a decisive influence on the dielectric properties of these doped s…
Colossal magnetoresistance without phase separation: Disorder-induced spin glass state and nanometer scale orbital-charge correlation in half doped manganites
R. Mathieu, D. Akahoshi, A. Asamitsu +2
The magnetic and electrical properties of high quality single crystals of -site disordered (solid solution) LnBaMnO are investigated near the phase boundary…
Impurity-induced transition to a Mott insulator in SrRuO
R. Mathieu, A. Asamitsu, Y. Kaneko +8
The electrical, magnetic, and structural properties of Sr(RuMn)O (0 0.2) are investigated. The parent compound SrRuO is a paramagn…
Temperature Dependent Magnetic and Structural Properties of Al Substituted Nanostructured Ferrites with Large Coercive Fields
P. Maltoni, R. K. Dokala, P. Pramanik +12
We report a comprehensive study of the temperature-dependent structural, magnetic, vibrational, and dielectric properties of Al-substituted M-type hexaferrites SrFeAlO…
Structural and magnetic properties of GaMnAs layers with high Mn content grown by Migration Enhanced Epitaxy on GaAs(100) substrates
J. Sadowski, R. Mathieu, P. Svedlindh +8
We have grown the ferromagnetic semiconductor GaMnAs containing up to 10% Mn by migration enhanced epitaxy at a substrate temperature of 150^oC. The alternate supply of As2 molecul…
A systematic method to identify runaways from star clusters produced from single-binary interactions: A case study of M67
A. Herrera-Urquieta, N. Leigh, J. Pinto +9
One hypothesis for runaway stars (RSs) is that they are ejected from star clusters with high velocities relative to the cluster center-of-mass motion. There are two competing mecha…
Variation of charge/orbital ordering in layered manganites Pr1-xCa1+xMnO4 investigated by transmission electron microscopy
X. Z. Yu, R. Mathieu, T. Arima +9
Structural features of the charge/orbital ordering (CO/OO) in single-layered manganites Pr1-xCa1+xMnO4 have been investigated systematically by transmission electron microscopy. An…
Magnetic Properties of Short Period InGaMnAs/InGaAs Superlattices
J. Sadowski, R. Mathieu, P. Svedlindh +4
We have observed a paramagnetic-to-ferromagnetic phase transition in short period InGaMnAs/InGaAs superlattices. The thicknesses of magnetic InGaMnAs layers in the structures studi…
Memory and rejuvenation in a spin glass
R. Mathieu, M. Hudl, P. Nordblad
The temperature dependence of the magnetisation of a Cu(Mn) spin glass ( 57 K) has been investigated using weak probing magnetic fields ( = 0.5 or 0 Oe) and speci…
Preparation, structural, dielectric and magnetic properties of LaFeO3-PbTiO3 solid solutions
S. A. Ivanov, R. Tellgren, F. Porcher +7
Solid solutions of (1-x)LaFeO3-(x)PbTiO3 (0<x<1) have been prepared by conventional solid-state reaction. These complex perovskites have been studied by means of X-ray (XRPD) and n…
Temperature-dependent multi-k magnetic structure in multiferroic Co3TeO6
S. A. Ivanov, R. Tellgren, C. Ritter +6
A complex magnetic order of the multiferroic compound Co3TeO6 has been revealed by neutron powder diffraction studies on ceramics and crushed single crystals. The compound adopts a…
Magnetization of ultrathin (Ga,Mn)As layers
R. Mathieu, B. S. Sørensen, J. Sadowski +6
Kerr rotation and Superconducting QUantum Interference Device (SQUID) magnetometry measurements were performed on ultrathin (GaMn)As layers. The thinner layers (b…
Thermally induced magnetic relaxation in square artificial spin ice
M. S. Andersson, S. D. Pappas, H. Stopfel +6
The properties of natural and artificial assemblies of interacting elements, ranging from Quarks to Galaxies, are at the heart of Physics. The collective response and dynamics of s…
Enhancement of antiferromagnetic interaction and transition temperature in M3TeO6 systems (M = Mn, Co, Ni, Cu)
R. Mathieu, S. A. Ivanov, P. Nordblad +1
Several M3 TeO6 (M = Mn, Co, Ni, Cu) oxides order antiferromagnetically at low temperatures (near or below 60 K), while displaying interesting dielectric properties at high tempera…
Anomalous Hall Effect and Magnetic Monopoles in Momentum-Space
Z. Fang, N. Nagaosa, K. S. Takahashi +7
Efforts to find the magnetic monopole in real space have been made in cosmic rays and in accelerators, but up to now there is no firm evidence for its existence due to the very hea…
Near room-temperature colossal magnetodielectricity and multiglass properties in partially-disordered La2NiMnO6
D. Choudhury, P. Mandal, R. Mathieu +8
We report magnetic, dielectric and magnetodielectric responses of pure monoclinic bulk phase of partially-disordered La2NiMnO6, exhibiting a spectrum of unusual properties and esta…
Structural and magnetic properties of Mn3-xCdxTeO6 (x = 0, 1, 1.5 and 2)
S. A. Ivanov, R. Mathieu, P. Nordblad +4
Mn3TeO6 exhibits a corundum-related A3TeO6 structure and a complex magnetic structure involving two magnetic orbits for the Mn atoms [*]. Mn3-xCdxTeO6 (x=0, 1, 1.5 and 2) ceramics…
Determination of the intrinsic anomalous Hall effect of SrRuO
R. Mathieu, C. U. Jung, H. Yamada +3
The anomalous Hall effect (AHE) of epitaxial SrRuO films with varying lattice parameters is investigated, and analyzed according to the Berry-phase scenario. SrRuO thin fil…
Investigation of the magnetic phase transition and magnetocaloric properties of the MnFeSbO ilmenite
M. Hudl, R. Mathieu, P. Nordblad +3
The magnetic phase transition and magnetocaloric properties of mineral and synthetic melanostibite MnFeSbO with ilmenite-type structure have been studied. MnFeSbO o…
Neutron diffraction studies and the magnetism of an ordered perovskite: Ba2CoTeO6
S. A. Ivanov, P. Nordblad, R. Mathieu +2
The complex perovskite Ba2CoTeO6 (BCTO) has been synthesised, and the crystal structure and magnetic properties have been investigated using a combination of X-ray and neutron powd…
Comment on "Quantum and Classical Glass Transitions in LiHoYF" by C. Ancona-Torres, D.M. Silevitch, G. Aeppli, and T. F. Rosenbaum, Phys. Rev. Lett. 101, 057201 (2008)
P. E. Jönsson, R. Mathieu, W. Wernsdorfer +2
We show in this comment that the claim by Ancona-Torres et al. of an equilibrium quantum or classical phase transition in the LiHoYF system is not supported by a ri…
Magnetotransport in a bi-crystal film of La_0.7Sr_0.3MnO_3
R. Mathieu, P. Svedlindh, R. Chakalov +1
Transport properties of an epitaxial film of La_0.7Sr_0.3MnO_3 (LSMO), deposited epitaxially on a LaAlO_3 bi-crystal substrate having a misorientation angle of 9.2 deg., have been…
Memory and superposition in a spin glass
R. Mathieu, P. Jönsson, D. N. H. Nam +1
Non-equilibrium dynamics in a Ag(Mn) spin glass are investigated by measurements of the temperature dependence of the remanent magnetisation. Using specific cooling protocols befor…
Constraints on blue straggler formation mechanisms in Galactic globular clusters from proper motion velocity distributions
N. W. C. Leigh, T. Panurach, M. Simunovic +10
For a sample of 38 Galactic globular clusters (GCs), we confront the observed distributions of blue straggler (BS) proper motions and masses (derived from isochrone fitting) from t…
Re-entrant superspin glass phase in LaCaMnO ferromagnetic insulator
P. Anil Kumar, R. Mathieu, P. Nordblad +4
We report results of magnetization and ac susceptibility measurements down to very low fields on a single crystal of the perovskite manganite, LaCaMnO. This c…
Voids and Mn-rich inclusions in a (Ga,Mn)As ferromagnetic semiconductor investigated by transmission electron microscopy
A. Kovacs, J. Sadowski, T. Kasama +5
Voids adjacent to both cubic (ZnS-type) and hexagonal (NiAs-type) Mn-rich nanocrystals are characterized using aberration-corrected transmission electron microscopy in annealed Ga0…
Ferrimagnetism, Antiferromagnetism and Magnetic Frustration in LaSrCuRuO (0 <= x <= 1)
P. Anil Kumar, R. Mathieu, R. Vijayaraghavan +6
We studied structural and magnetic properties of a series of insulating double perovskite compounds, LaSrCuRuO (0 x 1), representing doping via \tex…
Photoemission studies of GaMnAs: Mn-concentration dependent properties
H. Asklund, L. Ilver, J. Kanski +2
Using angle-resolved photoemission, we have investigated the development of the electronic structure and the Fermi level pinnning in GaMnAs with Mn concentrations in…
Isothermal remanent magnetization and the spin dimensionality of spin glasses
R. Mathieu, M. Hudl, P. Nordblad +5
The isothermal remanent magnetization is used to investigate dynamical magnetic properties of spatially three dimensional spin glasses with different spin dimensionality (Ising, XY…
Chemical pressure effects on structural, dielectric and magnetic properties of solid solutions Mn3-xCoxTeO6
S. A. Ivanov, R. Mathieu, P. Nordblad +6
The effects of Co2+ doping on the structural, magnetic and dielectric properties of the multiferroic frustrated antiferromagnet Mn3TeO6 have been investigated. Ceramic samples of t…
Reentrant spin glass transition in LaNdKMnO: origin and effects on the colossal magnetoresistivity
R. Mathieu, P. Svedlindh, P. Nordblad
Magnetic, electric and structural properties of LaNdKMnO with 00.4 have been studied experimentally. A disordered magnetic state is fo…
Electronic self-organization in the single-layer manganite
F. Ye, Songxue Chi, J. A. Fernandez-Baca +7
We use neutron scattering to investigate the doping evolution of the magnetic correlations in the single-layer manganite , away from the …
Scaling of the anomalous Hall effect in SrCaRuO
R. Mathieu, A. Asamitsu, H. Yamada +5
The anomalous Hall effect (AHE) of ferromagnetic thin films of SrCaRuO (0 0.4) is studied as a function of and temperature . As increases…