63 research outputs found
Critical properties of coupled anisotropic Haldane spin chains in a magnetic field
No full textWe use inelastic neutron scattering to measure magnetic fluctuations as a function of transverse magnetic field and temperature in a single crystal of the coupled Haldane chain compound SrNi2V2O8 with uniaxial anisotropy. At the base temperature 2 K , spin excitations confirm a field induced quantum phase transition from the disordered Haldane gapped singlet state to a gapped long range ordered state through a quantum critical point QCP amp; 956;0Hc amp; 8776; 11.5 T . At elevated temperatures in the vicinity of the QCP, both the energy and linewidth of the lowest triplet mode scale linearly with temperature, in accordance with quantum criticality. We also demonstrate that the experimental field dependence of the triplet excitation modes at the base temperature is in agreement with the bosonic and macroscopic models, but is in contrast to the fermionic and perturbative model
Modified Perfusion Fluid for Renal Transplantation in Developing Countries: Our Initial Experience
No full textPhonon excitations in the quasi-one-dimensional Haldane phase of SrNi₂V₂O₈
No full textVibrational Raman spectra of a single crystal of the coupled Haldane chain compound SrNi₂V₂O₈ with uniaxial anisotropy were investigated in the 10–1000 cm⁻¹ frequency range at temperatures 7–300 K. No structural phase transition was observed. The number of phonon lines observed in the experiment and their intensity were analyzed on the basis of the local symmetry considerations of different structural complexes. This approach was successful in explaining the discrepancy between the numbers of expected and experimentally observed phonon lines. Closeness of a real arrangement of some structural units to higher symmetry than the Wyckoff position results in strong interferential quenching of a number of Raman lines in the spectra
Superconductor insulator phase transition in single crystal La2 xSrxCuO4 films grown by the liquid phase epitaxy method
No full textOptical Floating Zone Growth of Large Single Crystal of Spin Half Dimer Sr3Cr2O8
No full textLarge single crystals similar to 6 mm in diameter and 35 50 mm in length of spin dimer system Sr3Cr2O8 have bee grown in a four mirror type optical floating zone furnace under different atmospheres. Single crystals were characterized by polarized optical microscopy, energy dispersive X ray analysis, X ray powder diffraction, X ray, and neutron Lane measurements, etc. Crystals were grown under an optimized growth atmosphere of flowing 6 8 L min synthetic air found to be free of any impurities and excellent in quality. Characteristics of the Magnetic Susceptibility and magnetization along different crystallographic axes are also show
Ultrasound velocity measurements in orbital degenerate frustrated spinel MgV2O4
No full textUltrasound velocity measurements of the orbital degenerate frustrated spinel MgV2O4 are performed in the disorder free high purity single crystal which exhibits successive structural and antiferromagnetic phase transitions, and in the disorder introduced single crystal which exhibits spin glass like behavior. The measurements reveal coexisting two types of anomalous temperature dependence of the elastic moduli in the cubic paramagnetic phase Curie type softening with decreasing temperature, and softening with a characteristic minimum with decreasing temperature. These elastic anomalies should respectively originate from the coexisting orbital fluctuations and spin cluster excitation
Merlin s magic reveals quantum magnet behaviour
No full textHighlight in the ISIS Facility Annual Repor
Impact of Growth Environment on the Crystal Growth and Magnetic and Electronic Properties of Ba2NiWO6 Single Crystals
No full textThis study introduces the effect of growth atmosphere and pressure on the as grown crystals and the physical characterization of the double perovskite compound Ba2NiWO6 BNWO . The Ni2 ions form a face centered cubic FCC lattice with an ideal octahedral arrangement. Our growth trials by the floating zone method revealed that BNWO exhibits two distinct colors depending on the growth atmosphere, suggesting that it influences its stoichiometry and phase purity. The antiferromagnetic properties of BNWO align with conventional antiferromagnetic behavior with a J 1 ground state, as determined by entropy calculation. Additionally, surface photovoltage SPV spectroscopy indicates that the impurity levels within the crystal influence the electronic properties of BNW
Optimization of single crystal growth of candidate quantum spin ice Pr2Hf2O7 by optical floating zone method
No full textGrowth of Ba2CoWO6 single crystals and their magnetic, thermodynamic and electronic properties
No full textThis study explores the bulk crystal growth, structural characterization, and physical property measurements of the cubic double perovskite Ba2CoWO6 BCWO . In BCWO, Co2 ions form a face centred cubic lattice with non distorted cobalt octahedra. The compound exhibits long range antiferromagnetic order below TN 14 K. Magnetization data indicated a slight anisotropy along with a spin flop transition at 10 kOe, a saturation field of 310 kOe and an ordered moment of 2.17 amp; 956;B at T 1.6 K. Heat capacity measurements indicate an effective j 1 2 ground state configuration, resulting from the combined effects of the crystal electric field and spin orbit interaction. Surface photovoltage analysis reveals two optical gaps in the UV Visible region, suggesting potential applications in photocatalysis and photovoltaics. The magnetic and optical properties highlight the significant role of orbital contributions within BCWO, indicating various other potential application
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