Neutron diffraction study of the Néel transition in Cr(0.5% V)

Abstract

While pure chromium undergoes a first-order antiferromagnetic transition, thermal expansion measurements have indicated that the addition of small amounts of vanadium and molybdenum make the Néel transition continuous. A neutron diffraction study of a single crystal of Cr(0.5% V) showed no discontinuity in magnetic Bragg satellite intensity at the Néel temperature, TN=254 K, that would indicate a first-order transition. Complicated behavior of the satellite intensities near the transition temperature is attributed to inhomogeneous strain in the sample. The satellite intensity showed a linear temperature dependence over a range of at least 100 K below TN.

Proximity effect of vanadium on spin-density-wave magnetism in Cr films

“…In the present Cr/V system we find a quasi-linear temperature dependence of I(t) at low temperatures, which resembles the temperature dependence observed in CrV alloys [52], but which is drastically different from the I(t) dependence seen in bulk Cr and other thin films. Noakes et al [52] speculated that the unusual I(t) behavior may not be an intrinsic feature of the CrV alloy, but due to strain effects. From our analysis it appears that the I(t)…”

“…The data are plotted in Fig.6 and compared to the SDW period in bulk Cr [43] and in a 2000Å thick Cr film grown on a thick Nb buffer layer [48]. Since no data are available for thin CrV films, we compare our results with a bulk Cr 0.995 V 0.005 alloy [52,53,54]. This of the SW period in our Cr/V film is similar to that in other Cr thin film systems and in bulk Cr, but completely different from that in the Cr 0.995 V 0.005 alloy.…”

Onset of spin-density-wave antiferromagnetism inCr∕Vmultilayers

“…26͒ and bulk Cr 0.995 V 0.005 alloy. 27 The SDW period in Cr/ V does not follow the temperature dependence observed in CrV alloys and appears to be more similar to results reported for thin Cr films, 3 where it is enhanced compared to bulk Cr and scales inversely with the Cr thickness. The exception is the Cr͑2000 Å͒ / V sample where the SDW period is smaller than in bulk Cr, which is highly atypical for thin Cr films.…”

Proximity effect of vanadium on strain and spin-density waves in thin Cr films

“…The spin-density wave and strain wave properties were investigated by a combination of synchrotron scattering experiments to probe the strain waves and elastic neutron scattering to probe the spin-density waves in the Cr film. It was shown that the V-Cr hybridization at the interface causes a strong and long-range influence on the SDW behavior in the [16], bulk Cr [14], and integrated intensity of the spin-density wave satellite reflections measured with neutron scattering in bulk CrV alloy with a V concentration of 0.5 at% (from Noakes et al [15]). …”

“…The data are plotted in Fig. 5 and compared to the SW period in bulk Cr [14] and Cr 0.995 V 0.005 alloy [15]. This CrV alloy composition corresponds roughly to the same composition as Cr(2000 Å )/V(14 Å ) when mixed, which would result in a 0.7 at% alloy.…”