Magnetic properties of some cerium-based alloys

Thermal annealing effects on the magnetic behavior of Ce2NiSi3

“…The X-ray powder diffraction experimental data show that the Ce 2 NiSi 3 alloy crystallizes in the hexagonal AlB 2 structure, P 6/ mmm(191) space group, with lattice parameters a¼4.0485(1)Å and c¼4.2877(2)Å, in good agreement with those reported in the literature [5,9]. The La 2 NiSi 3 alloy displays the same structure but with a¼4.0711(5)Å and c¼4.3737(7)Å.…”

“…Thus, the Kondo effect could account for the reduction of the magnetic entropy at the transition. In this sense, the electrical resistivity measurements in the CeNi 0.5 Si 1.5 alloy [9] (with the same compositional ratio as the sample studied in the present work) show a local minimum around 20 K, followed by a maximum at the magnetic transition. Similar features were found in the isotypic Ce 2 NiIn 3 alloy [7], where an increase, characteristic of the Kondo effect, between a local minimum at 15 K and a maximum at 4 K, was observed.…”

“…On the other hand, a significant number of the 2:1:3 compounds present spin-glass behavior, usually attributed to the disorder of the non-magnetic atoms in the T-X plane, characteristic of the AlB 2 structure [3,7,8]. Among the R 2 TX 3 series of alloys, the Ce 2 NiSi 3 one presents a peak close to 3 K in the specific heat [9], while the magnetic susceptibility data show an increase as the temperature is decreased [5]. However, the low temperature data of this alloy was not properly addressed in the literature, probably because, in those studies, the point of interest was above the magnetic transition.…”

Magnetic ordering and Kondo behavior in single-crystalline Ce2NiSi3

“…22 Two of them, namely, Ce 2 NiGe 3 and Ce 2 NiIn 3 , have been characterized as spin glasses with the freezing temperature of 3.5 and 2.8 K, respectively. 23,24 In contrast, in Ce 2 NiSi 3 an antiferromagnetic ground state has been revealed by means of magnetic susceptibility and heat-capacity measurements of polycrystalline samples, 25,26 which seemed fairly unexpected for a R 2 T M 3 compound with a strongly disordered unit cell. However, specimens prepared in different laboratories showed somewhat divergent bulk characteristics, 18,25,26 and the Néel temperature appeared notably dependent on postcast thermal treatment of polycrystalline material.…”

Element segregation during crystal growth processes of Ce2PdxCo1−xSi3 intermetallic compounds

“…In the past decade Ce 2 TMSi 3 (TM ¼ transition metal Co, Pd, Ni, Au) intermetallic compounds with AlB 2 -type hexagonal crystal structure have become a subject of great scientific interest because of their complex magnetic ordering and related phenomena [1]. The competition of magnetic ordering and Kondo-type behaviour in substitution intermetallic compounds are of particular importance [2,3].…”