Magnetism and crystal field in NdCu5

Crystal structure and magnetic properties of RCu5−xPdx (R=Pr, Nd, Sm and Eu) alloys

“…Evidence for a crystal electric field level located just $2 meV above the ground state in NdCu 5 , inferred from strong quasi-elastic and unresolved inelastic broadening in the neutron spectrum, is reported in Ref. [20]. The presence of appreciable Schottky specific heat in the paramagnetic region may be an additional reason for a reduced jump in the heat capacity at the magnetic transition at 11 K.…”

“…The broad peak, like in the Pr analogues, may be due to local environment effects arising from the random replacement of Cu by Pd in the ternary alloys. The parent NdCu 5 also shows a relatively small jump at T c ¼ 14.5 K [20], possibly due to a second spin re-orientation transition at T R ¼ 5.6 K such that the entropy due to the magnetic ordering is distributed over a longer interval of temperature. A minor anomaly near 6 K in the heat capacity of NdCu 4 Pd, corresponding to the anomaly in the susceptibility near the same temperature, reveals that spin re-orientation may be occurring in the pseudo-ternary alloy as well.…”

“…LaCu 5 is a Pauli paramagnet while PrCu 5 shows nearly temperature independent van-Vleck susceptibility below 4.2 K due to a singlet ground state [18]. RCu 5 for R ¼ Nd, Sm, Eu and Gd undergo long range magnetic ordering at $14.5 [19,20], 9 [21], 57 [15] and 25 K [22], respectively. While SmCu 5 and GdCu 5 are antiferromagnetic, NdCu 5 orders ferromagnetically at $14.5 K and undergoes spin re-orientation at lower temperature.…”

Structure and Magnetic Property of High‐Entropy Intermetallics Based on SmCo5 with the Equiatomic Ratios at Sm and Co Sites

“…According to previous studies, doping Cu into CeCo 5 causes the increase in coercivity due to the Ce valent state changes from Ce 4þ to Ce 3þ . [27,28] In Nd-Cu binary system, NdCu 5 intermetallic compound shows ferromagnetic order below 14.5 K and spin reorientation transition at 5.6 K. [29] In the R-Ni binary system, Ni atom does not essentially contribute to the spontaneous magnetic moment due to its filled 3d orbital. However, the 4f orbital of rare earth is unfilled.…”