Magnetic Properties of DyAl2 and NdAl2

Abstract

The magnetic properties of two dialuminides, DyAl2 and NdAl2, have been investigated by neutron diffraction and susceptibility measurements. Both compounds show Curie-Weiss behavior in the paramagnetic region and are basically ferromagnetic below Curie temperatures of 62°K and 65°K, respectively. At low temperatures, the compound NdAl2 is a pure ferromagnet, whereas DyAl2 is almost completely ferromagnetic, but has the additional property of a weak antiferromagnetic ordering. The susceptibility measurements show an effective moment per molecule of 9.7±0.1 and 3.1±0.05 μB for DyAl2 and NdAl2, respectively. The neutron diffraction data show a rare-earth-ordered saturation moment of 9.1±0.4 and 2.5±0.1 μB on the Dy and Nd atom sites, respectively. The Al atom sites exhibit no measureable moment within the limits of experimental detection (0.5 μB). Both compounds show a temperature-dependent magnetic ordering process which obeys a Brillouin function. The experimental magnetic form factor for both the Dy3+ and Nd3+ ions diminishes more rapidly with increasing (sinθ)/λ than present theory postulates.

Magnetic susceptibility and parameters of electronic structure of Al2REM (Gd, Dy, and Ho) intermetallic compounds at high temperatures

“…Figure 2 shows the temperature dependences χ(T) for the Al 2 Dy and Al 2 Ho intermetallic compounds together with the well-known literature data. A comparison of the results obtained for the Al 2 Dy compound demonstrates that they agree satisfactorily with the data presented in [2]; on the contrary, the χ values differ by 12-14% from those reported in [6] for the entire examined temperature interval. A comparison of our experimental data with the results presented in [6] demonstrated that for the Al 2 Ho intermetallic compound, the χ values differed only for the liquid state.…”

“…2. Temperature dependences of the magnetic susceptibility: a) Al 2 Dy intermetallic compound (curve 1 shows data taken from [2], curve 2 shows data taken from [6], curve 3 shows our data obtained during heating, and curve 4 shows our data obtained during cooling) and b) Al 2 Ho intermetallic compound (curve 1 shows data taken from [6], curve 2 shows our data obtained during heating, and curve 3 shows our data obtained during cooling).…”

“…When determining the electronic characteristics, the temperature dependences of the magnetic susceptibility χ(T) above the phase transition points (Curie and Néel ones) were approximated by the classical Curie-Weiss law [2,3,6]. In this case, the paramagnetic contribution of the conduction electrons was disregarded, though these intermetallic compounds possess sufficiently low electric resistance ρ = 20-80 μΩ⋅cm at T = 300 K [7].…”

“…The magnetic susceptibility and neutron diffraction were investigated in [2] for the Al 2 Dy compounds at temperatures in the range 50-310 K. Based on the experimental results, the effective magnetic moment per dysprosium atom was calculated; it was equal to μ eff = (9.7 ± 0.1)μ B , and the Debye temperature T D = (140 ± 15) K was determined for this compound. Al 2 Ho powder samples were investigated by the neutron diffraction method.…”

Use of Stevens coefficients for the prediction of magnetic transitions in pseudobinaryR1−xRx'AlKhan1, Paudyal2, Mudryk3 et al. 2011Phys. Rev. B141100View full textAdd to dashboardCite

“…1,2,3,4,5 Specifically the isostructural RAl 2 compounds are well known for interesting properties including crystalline electric field effects 5 and low temperature ferromagnetism 4,5 that can be controlled by varying the rare earth component. Recent research results suggest that despite of broad experimental and theoretical investigations that have been already performed using these relatively simple MgCu 2 -type Laves phases, some fascinating and new phenomena in the RAl 2 compounds are yet to be discovered.…”