Van Vleck paramagnetism of the trivalent Eu ions

Abstract

a b s t r a c tMagnetic susceptibilities of Eu 2 O 3 , EuF 3 and EuBO 3 have been measured over the wide temperature range 5-650 K. The Van Vleck paramagnetism, with the ground state of 7 F 0 (S ¼ 3, L¼ 3), has been investigated comprehensively. The temperature independent paramagnetism emerges manifestly below approximately 100 K. The variation of the susceptibility with temperature for EuBO 3 is in satisfactory agreement with the coupling constant l ¼ 471 K, where the spin-orbit interaction is lL Á S for the Russell-Saunders coupling on the basis of Van Vleck theory with one parameter l. The value of l ¼ 490 K can fit the susceptibility data of EuF 3 . The deviation from the theory arises in Eu 2 O 3 . This discrepancy originates mainly from the influence of the crystalline field. Susceptibility of Gd 2 O 3 , having the ground state of 8 S 7/2 (S ¼ 7/2, L ¼0), is also presented as a magnetic standard compound in comparison with these results.

Ba2YIrO6: A cubic double perovskite material withIr5+ions

“…5). This fitting gives a temperature independent susceptibility contribution χ 0 = 5.83 × 10 Below ∼ 15 K, deviations from the CW fitting occur, which probably stem from even larger antiferromagnetic spin correlations in the low-temperature regime, or from a small temperature-dependent contribution to the Van Vleck susceptibility, which has not been taken into account in the fit but which has been observed, e.g., for Eu 3+ [32].…”

Eu-doped α-Fe2O3 nanoparticles with modified magnetic properties

“…The role of Eu doping of the magnetic response of hematite nanoparticles can be put in evidence starting from the following considerations: a) trivalent Eu ions have an effective magnetic moment μeff≅3.3-3.5 μB around room temperature [38]; this is markedly smaller than that of Fe3+ ions (μeff=5.9 μB); b) rare-earth ions are characterized by a strong single-ion magnetic anisotropy arising from spin-orbit coupling [39] and higher than the one exhibited by transition metal ions.…”

Magnetic Studies of EuBa2Cu3-xRuxO7-δCompounds

“…Thus, e.g., the experimental value of µ eff of Eu 3+ ions obtained by measurements of Eu 2 O 3 at 300 K is near 3.4 µ B [7], opposite to zero predicted by the Hand rule.…”