Dapeng Chen

Magnetic properties in polycrystalline and single crystal Ca-doped LaCoO3

Polycrystalline (PC) and single crystalline (SC) Ca-doped LaCoO3 (LCCO) samples with the perovskite structure were synthesized by conventional solid-state reaction and the floating-zone growth method. We present the results of a comprehensive investigation of the magnetic properties of the LCCO system. Systematic measurements have been conducted on dc magnetization, ac susceptibility, exchange-bias, and the magnetocaloric effect. These findings suggest that complex structural phases, ferromagnetic (FM), and spin-glass/cluster-spin-glass (CSG), and their transitions exist in PC samples, while there is a much simpler magnetic phase in SC samples. It was also of interest to discover that the CSG induced a magnetic field memory effect and an exchange-bias-like effect, and that a large inverse irreversible magnetocaloric effect exists in this system.

Single-crystal growth and investigation of NaxCoO2and NaxCoO2.yH2O

A systematic study of NaxCoO2 (x=0.50 - 0.90) and NaxCoO2 yH(D)2O (x=0.26 - 0.42, y=1.3) has been performed to determine phase stability and the effect of hydration on the structural and superconducting properties of this system. We show that a careful control of the Na deintercalation process and hydration dynamics is possible in single crystals of this system. Furthermore, we give experimental evidence that the dependence of the superconducting transition temperature on Na content is much weaker than reported earlier. Implications of this effect for the understanding of the superconducting phase diagram are discussed.

Spin singlet pairing in the superconducting state of NaxCo02 1.3H2O: evidence from a 59Co Knight shift in a single crystal

We report a

Domain wall conductivity in oxygen deficient multiferroic YMnO3 single crystals

^{59}\mathrm{Co}

Multivariate Statistical Characterization of Charged and Uncharged Domain Walls in Multiferroic Hexagonal YMnO3 Single Crystal Visualized by a Spherical Aberration-Corrected STEM

Knight-shift measurement in a single crystal of the cobalt oxide superconductor

Oxygen-vacancy effect on structural, magnetic, and ferroelectric properties in multiferroic YMnO3 single crystals

{\mathrm{Na}}_{x}\mathrm{Co}{\mathrm{O}}_{2}∙1.3{\mathrm{H}}_{2}\mathrm{O}

Manipulation of domain wall mobility by oxygen vacancy ordering in multiferroic YMnO3

({T}_{c}=4.25\phantom{\rule{0.3em}{0ex}}\mathrm{K})

Orbital structure of FeTiO3 ilmenite investigated with polarization-dependent X-ray absorption spectroscopy and band structure calculations

. We find that the shift due to the spin susceptibility,

Magnetic anisotropy in doped and undoped LiFePO4 single crystals

{K}^{s}