Structures and magnetic properties of Tm1−y Y y Mn1−x Co x O3

Abstract

The structure and magnetic properties of Tm 1−y Y y Mn 1−x Co x O 3 with 0x 0.5 and 0 y 0.3 were investigated by X-ray diffraction, specific heat and magnetization measurements. Thulium manganite TmMnO 3 prepared by solid-state synthesis at ambient pressure is hexagonal and antiferromagnetic with a Nèel temperature T N of 86 K. The substitution of Y for Tm in TmMnO 3 does not greatly affect the fundamental hexagonal structure. The magnetization and specific heat measurement results for Tm 1−y Y y MnO 3 can be qualitatively explained in terms of the dilution effect of Tm by Y. On the other hand, the structure of TmMn 1−x Co x O 3 changes gradually from hexagonal to orthorhombic with the substitution of Co for Mn; hexagonal and orthorhombic phases coexist in samples for x 0.3 whereas TmMn 0.6 Co 0.4 O 3 is almost a single orthorhombic phase. The magnetization of TmMn 0.6 Co 0.4 O 3 in a field of 250 Oe increases rapidly at about 60 K with decreasing temperature. The difference between zero-field-cooled (ZFC) and field-cooled (FC) magnetizations increases remarkably at about 60 K. Moreover, the temperature dependences of the ZFC and the FC magnetizations exhibit peaks at about 40 and 30 K, respectively. Thus, TmMn 1−x Co x O 3 exhibits complex magnetic properties.

Theory of surface Andreev bound states and tunneling spectroscopy in three-dimensional chiral superconductors

“…When the penetration depth is much larger than the coherence length of superconductor, this approximation does work as far as we are discussing surface Andreev bound states and innergap tunneling conductance. This approximation has been actually done in the previous work in Eilenberger equation 66 and qualitatively reasonable results are obtained. Also, these results are qualitatively same as the results obtained by extended version of BTK theory 20 .…”

Quasi-Classical Theory of Tunneling Spectroscopy in Superconducting Topological Insulator

“…These features have never been seen in Doppler effect in high-T c Cuprate, where the ABS has a flat dispersion. [67][68][69] Next, we show the case of µ S = 0.7 eV in Fig. 12.…”

Effect of Co Doping on the Structure and Magnetic Properties of TmMn1−xCoxO3

“…Quantitative differences due to sample preparation were minimal, and similar results have been reported previously. 14) For 0.5≤x≤0.9, the CP method was used.…”

“…In TmMn1-xCoxO3 prepared by a solid-phase reaction, the substitution of Mn with Co induced a hexagonal-to-orthorhombic transformation for 0≤x≤0.5, and the samples with x≥0.4 became almost single-phase orthorhombic. 14) In the Co-substituted system, the magnetization increased ferromagnetically at about 60 K with decreasing temperature, and had a maximum at around 30 K. The maximum magnetization increased with x for 0≤x≤0.5. For x≥0.5, the amount of Tm2O3 impurity increased with x.…”

“…Figures 3 and 4 plot, respectively, the temperature dependences of the field-cooled (MFC) and zero-field-cooled (MZFC) magnetization for the 0≤x≤0.4 SSR samples 14) and the 0.5≤x≤0.9 CP samples in a magnetic field of 250 Oe. The insets of Figs.…”