No abstract

DC magnetization and AC susceptibility measurements point to the formation of a spin glass state in the ternary spinel-type compounds Li 1.33x Co 2−2x Ti 1+0.67x O 4. The dynamics of spin freezing was analysed with both the critical slowing down and the thermally activated dynamics models. The parameter values obtained, as well as the behaviour of the zero-field-cooled and field-cooled magnetization as a function of temperature, indicate the existence of a cluster glass state in disordered spinel samples with x = 0.25 and 0.40, and probably also in the ordered spinel with x = 0.50. Ordered spinel samples with x = 0.75 and 0.875 were found to be paramagnetic down to the temperature of 1.7 K with a random distribution of Co 2+ ions.

No abstract

No abstract

Low-temperature (300-4.2 K) electrical resistivity behaviours of as-cast glassy, relaxed, and crystallized Pd 40 Ni 10 Cu 30 P 20 alloys have been investigated. It is found that the resistivity of the as-cast glassy alloy is about 257 µ cm at ambient temperature and decreases with a temperature coefficient of resistivity (TCR) of 2.1 × 10 −4 K −1 in the temperature range of 280-50 K and 89 × 10 −4 K −1 in the temperature range of 12-4.2 K. The relaxation effect slightly increases the resistivity by a factor of about 10% while crystallization decreases the resistivity of the alloy. Surprisingly, we found that all samples, as-cast glassy, relaxed, crystallized, and well-crystallized alloys, exhibit similar temperature dependences of the electrical resistivity in the temperature range investigated. TCR changes at around 10-20 K for all samples are linked with rapid increase of the magnetization in the alloys.Research into bulk metallic glass is currently one of the most dynamic areas of materials science, in which multicomponent alloys with a good glass-forming ability and wide supercooled liquid region have been fabricated [1,2]. PdCuNiP is known to be one of the best glass-forming systems for forming glasses with a diameter of up to 72 mm [3]. A number of viscosity [4], diffusion [5], density [6], thermal expansion [7], structure [8], specific heat capacity [9], ultrasonic [10], crystallization at ambient pressure [11][12][13][14][15][16] and at high pressure [17], time-dependent nucleation [18], statistical variation of the nucleation process [19], multi-glass transition [20,21], and thermal conductivity [22] measurements have been performed on the glassy system. High-temperature (above 300 K) electrical resistivity measurements as a probe for glass and crystallization transitions were reported for 4 Author to whom any correspondence should be addressed.