123 research outputs found
Torque magnetometry studies of new low temperature metamagnetic states in ErNi_{2}B_{2}C
The metamagnetic transitions in single-crystal ErNiBC have been
studied at 1.9 K with a Quantum Design torque magnetometer. The critical fields
of the transitions depend crucially on the angle between applied field and the
easy axis [100]. Torque measurements have been made while changing angular
direction of the magnetic field (parallel to basal tetragonal -planes) in a
wide angular range (more than two quadrants). Sequences of metamagnetic
transitions with increasing field are found to be different for the magnetic
field along (or close enough to) the easy [100] axis from that near the hard
[110] axis. The study have revealed new metamagnetic states in ErNiBC
which were not apparent in previous longitudinal-magnetization and neutron
studies.Comment: 3 pages (4 figs. incl.) reported at 52th Magnetism and Magnetic
Materials Conference, Tampa, Florida, USA, November 200
Influence of high-energy electron irradiation on the transport properties of La_{1-x}Ca_{x}MnO_{3} films (x \approx 1/3)
The effect of crystal lattice disorder on the conductivity and colossal
magnetoresistance in La_{1-x}Ca_{x}MnO_{3} (x \approx 0.33) films has been
examined. The lattice defects are introduced by irradiating the film with
high-energy (\simeq 6 MeV) electrons with a maximal fluence of about 2\times
10^{17} cm^{-2}. This comparatively low dose of irradiation produces rather
small radiation damage in the films. The number of displacements per atom (dpa)
in the irradiated sample is about 10^{-5}. Nethertheless, this results in an
appreciable increase in the film resistivity. The percentage of resistivity
increase in the ferromagnetic metallic state (below the Curie tempetature
T_{c}) was much greater than that observed in the insulating state (above
T_{c}). At the same time irradiation has much less effect on T_{c} or on the
magnitude of the colossal magnetoresistance. A possible explanation of such
behavior is proposed.Comment: RevTex, 22 pages, 3 Postscript figures, submitted to Eur. Phys. J.
Investigation of the superconducting energy gap in the compound LuNiBC by the method of point contact spectroscopy: two-gap approximation
It is shown that the two-gap approximation is applicable for describing the
spectra of LuNiBC-Ag point contacts in a wide interval
of temperatures. The values and the temperature dependences of the large and
the small gaps in the plane and in the direction were estimated using
the generalized BTK model and the equations of Beloborodko. In the BCS
extrapolation the critical temperature of the small gap is 10 in the
plane and 14.5 in the direction. The absolute values of the gaps are
and . For the large gaps the
critical temperature coincides with the bulk , , and
their absolute values are very close, being about 3 in both orientations.
In the direction the contributions to the conductivity from the small and
the large gaps remain practically identical up to . In the
plane the contribution from the small gap is much smaller and decreases rapidly
as a temperature rises.Comment: 10 pages, 10 figures, submitted to Fiz. Nizk. Temp. (Low Temp. Phys.
Torque magnetometry studies of metamagnetic transitions in single-crystal HoNi_{2}B_{2}C and ErNi_{2}B_{2}C at T\approx 1.9 K
The metamagnetic transitions in single-crystal rare-earth nickel borocarbide
HoNi_{2}B_{2}C and ErNi_{2}B_{2}C have been studied at 1.9 K with a Quantum
Design torque magnetometer. The critical fields of the transitions depend
crucially on the angle between applied field and the easy axis [110] for
HoNi_2B_2C and [100] for ErNi_2B_2C. Torque measurements have been made while
changing angular direction of the magnetic field (parallel to basal tetragonal
ab-planes) in a wide angular range (more than two quadrants). The results are
used not only to check and refine the angular diagram for metamagnetic
transitions in these compounnds, but also to find new features of the
metamagnetic states. Among new results for the Ho borocarbide are the influence
of a multidomain antiferromagnetic state, and ``frustrated'' behavior of the
magnetic system for field directions close to the hard axis [100]. Torque
measurements of the Er borocarbide clearly show that the sequence of
metamagnetic transitions with increasing field (and the corresponding number of
metamagnetic states) depends on the angular direction of the magnetic field
relative to the easy axis.Comment: 3pages (4 figs. incl.) reported at 50th Magnetism and Magnetic
Materials Conference, San Jose, CA, USA, 200
Transport, thermal and magnetic properties of RuSr_2(Gd_{1.5}Ce_{0.5})Cu_2O_{10-\delta}, a magnetic superconductor
Resistivity, thermoelectric power, heat capacity and magnetization for
samples of RuSr_2(Gd_{1.5}Ce_{0.5})Cu_{2}O_{10-\delta} were investigated in the
temperature range 1.8-300 K with a magnetic field up to 8 T. The resistive
transitions to the superconducting state are found to be determined by the
inhomogeneous (granular) structure, characterized by the intragranular, T_{c0},
and intergranular, T_{cg}, transition temperatures. Heat capacity, C(T), shows
a jump at the superconducting transition temperature T_{c0}\approx 37.5 K. A
Schottky-like anomaly is found in C(T) below 20 K. This low temperature anomaly
can be attributed to splitting of the ground term of paramagnetic
Gd^{3+} ions by internal and external magnetic fields.Comment: 3 pages (4 figs. incl.), reported at 50th Magnetism and Magnetic
Materials Conference, San Jose, CA, USA, 200
Psychological Factors Influencing Credit Card Usage of Employees in Colombo District, Sri Lanka
Credit card is one of the trending cashless transaction methods used worldwide with the advancement of technology. Records in Central Bank of Sri Lanka (CBSL) show the demand and the number of credit cards issued are increasing day by day due to different reasons. Researchers have revealed that different demographic, socio-economic and credit card attributes were reasons for use of credit cards among different types of credit card holders. But the influence of psychological factors is also a subject of considerable research. Therefore, the objective of this research is to identify the influential psychological factors on credit card usage of employees in the Colombo district. With the aid of different sampling techniques where necessary, 385 respondents were selected for the sample. Required data were collected through a structured questionnaire and psychological variables were measured by ten-point Likert Scale Statements. Multiple linear regression analysis was carried out with the aid of Minitab 20. Results of the study revealed that the perceived financial cost, user pattern, social status and attitudes are highly influential psychological factors while convenience and financial optimism have not significantly influenced the credit card usage of employees in the Colombo district. Future research is suggested to identify the influence of similar factors for other districts and commercial banks separately, and apply advanced analysis to identify the latent factors that affect credit card usage of employees in the Colombo district.
DOI: http://doi.org/10.31357/fhss/vjhss.v07i02.0
Low-temperature metamagnetic states in single crystal TbNi2B2C studied by torque magnetometry
Metamagnetic transitions in single crystalTbNi2B2C have been studied at 1.9 K with a Quantum Design torque magnetometer. The critical fields for the transitions depend strongly on the angle between the applied field and the easy axis [100]. Torque measurements have been made while changing the angular direction of the magnetic field (parallel to basal tetragonal ab-planes) at fixed field magnitude and while changing the field magnitude at fixed angular direction over a wide angular range (more than two quadrants). Torque magnetometry (sensitive only to the component of magnetization perpendicular to the field) indicates not only a different sequence of metamagnetic phases for fields near the easy axis from those near the hard axis, but also the different natures of a principal metamagnetic phase near the hard axis. Comparison of the results with longitudinal magnetization measurements is presented
An electron tunneling study of superconductivity in amorphous Sn(sub 1-x)Cu(sub x) thin films
The amorphous phase of Sn would have a superconducting transition temperature near 8 K, much higher than that of crystalline Sn with T(sub c) = 3.5 K. To obtain the amorphous phase, however, it is necessary to use a Sn alloy, usually Cu, and quench condense the alloy films onto a liquid He temperature substrate. Alloying with Cu reduces the superconducting transition temperature almost linearly with Cu concentration with an extrapolation of T(sub c) to zero for x = 0.85. Analysis of the tunneling characteristics between a normal metal electrode with an insulating barrier and superconducting amorphous Sn-Cu films provides detailed information on the changes in the electron-phonon coupling which determines T(sub c) in these alloys. The change from very strong electron-phonon coupling to weak-coupling with the increase in Cu content of amorphous Sn-Cu alloys for the range 0.08 is less than or equal to x is less than or equal to 0.41 is presented and discussed in terms of theories of electron-phonon coupling in disordered metals
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