Features of prerecrystallization processes in strongly deformed nickel foils

Antiferromagnetism in a Cr86Ru14 alloy

“…At low concentrations (c = 0.3 at.% Ru) the relationship is dT N /dc positive and dT N /dp negative, which give way to dT N /dc negative at c = 14 at.% Ru while dT N /dp remains negative. The present measurements confirm the negative sign that was previously [25] observed for dT N /dp for c = 14 at.% Ru, but differ substantially in the magnitudes of T N and dT N /dp for Cr 86 Ru 14 of the previous [25] measurements. (ii) The coupling of the CSDW to the lattice in the concentrated alloy is relatively weak compared to that in the very diluted alloy, resulting in much smaller magnetovolume effects and in the magnetic contribution to the longitudinal-mode elastic constant in the former than in the latter alloy.…”

“…Previous [25] measurements on Cr 86 Ru 14 (presumably nominal concentration) gave T N ≈ 480 K and dT N /dp = −29 K/GPa. These two values differ markedly from the observations of the present study as well as, in the case of T N , with the known [1] Cr-Ru alloy magnetic phase diagram.…”

Nanoparticle Films

“…For x > 0:16, the conductance still has activation characteristics but the temperature dependence cannot be described by using the above-mentioned law. Negative TCR suggests nonmetallic conductiv-ity such as semiconductor-like or amorphous-like activity [24,27]. The TCR at RT becomes positive for x > 0:35, while it is still negative for temperatures below 270 K. Metal conductance in a wide temperature range was observed only for x > 45.…”

“…The resistance of a reference film with polycrystalline structure is measured to be 50 µ cm. The enhanced l value can be attributed to the nanoscale size and interface effects [26,27]. The low value of h is caused by disorders in the composite film structure as well as partial alloying of Al 2 O 3 with Co and Fe during film deposition [30].…”

“…The size of the latter crystalline regions is about 1 nm. The formation of such a structure is typical for composite films and is caused by the low migration rate of oxide clusters that prevent coalescence and recrystallization of the metal phase [26,27] Additional structural information can be obtained and the evolution of the magnetic structure with concentration x can be conveniently studied by measuring the magnetic properties. Magnetization measurements demonstrate that the magnetic phase of the films changes from superparamagnetic to ferromagnetic with increasing x.…”