ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
At low temperature CdCr2xIn2−2xS4 spinel solid solutions show a ferromagnetic-spin-glass transition. In the present work the ac susceptibility measurements (130 Hz〈ν〈100 kHz) have been carried out on toroid-shaped samples, which allows us to minimize the macroscopic demagnetizing fields, by using a technique based on a direct flux determination. Our results are compared with previous measurements, performed by using standard methods. The shape of the χ'(ν) curves is similar to that obtained from the standard methods: no maximum in the transition temperature region (4 K〈Tg〈18 K); however, the χ' values are higher: as an example, for x=0.95, χ'max (approximately-equal-to)0.5 emu/cm3(approximately-equal-to)1/N (N being the demagnetizing factor) with standard methods, while our result is χmax ∼3.5 emu/cm3. Such a result is discussed notably with respect to the influence of porosity; a precise comparison should take into account the actual density of samples. Just below Tc (∼40–85 K), χ' does not depend on frequency, but we observe, in the transition temperature region, a decrease of χ' when ν increases. χ‘ presents two well-defined peaks around Tg and Tc. The latter maximum does not depend on frequency, while the first one shifts as a function of ν, which indicates dynamical effects (as an example for x=0.95, Tg =10.5 K at 130 Hz and Tg =13.0 K at 100 kHz).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.335079
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