The magnetic hyperfine field at Cd nuclei in the rare earth ferromagnets Gd, Tb, Dy, Ho, Er and Tm

Abstract

The time differential perturbed angular correlation technique has been used to study the combined magnetic and electric hyperfine interactions at the site of a 111Cd impurity in the rare earth ferromagnets Gd, Tb, Dy, Ho, Er, and Tm at 4.2 ~ The following magnetic hyperfine fields at the site of 111Cd have been found: [ ttt~f[ = 340(7) kG in Gd, 275 (5) kG in Tb, 221 (4) kG in Dy, 116 (3) kG in Er and 60 (6) kG in Tin.In Ho two magnetically different sites were observed with magnetic fields of 159 (3) and 139 (3) kG. Both sites are equally populated.The coupling constant Js f of the conduction electron-4f interaction has been calculated for the different rare earth metals from the measured hyperfine fields by means of the RKKY theory.

Perturbed angular distributions withLaBr3detectors: Thegfactor of the first10+state inCdGray1, Stuchbery2, Reed3 et al. 2017Phys. Rev. C63151View full textAdd to dashboardCite

“…A direct comparison between the G 22 (t) functions obtained in the off-line measurements, (Refs. [24,37,38]), and R(t) of the present measurements that apply a polarizing field, is not meaningful. However, G 22 (t) and the corresponding R(t) applicable to our experiment resulting from the combined electric-magnetic interaction can be evaluated.…”

“…The reaction excited the 107 Cd nucleus, populating the 846-keV, I π = 11 2 − state of interest with mean life τ = 107 3ns [13], and g factor g = −0.189(2) [22]. For a hyperfine field strength of B hf = −34.0(7) T [23,24] the expected precession period is T L = π/ω L ≈ 10 ns.…”

“…The combined electric-magnetic interaction has been examined thoroughly for the I π = 5 2 + 1 state of 111 Cd in gadolinium by studying the γ -γ angular correlations after 111 In decay [24,37,38]. Each of these experiments used an amorphous sample with no polarizing field.…”

“…Each of these experiments used an amorphous sample with no polarizing field. Thus the EFG and B hf are randomly oriented; however, there is a preferred angle (β) between V zz and B hf for any individual gadolinium microcrystal [24,[37][38][39]. In such experiments, the time-dependent angular correlation function can be expressed as…”

The Temperature Dependence of the Magnetic Hyperfine Field at 111Cd in Magnetically Ordered Holmium

“…The radioactive -3 impurity concentration was less than 10 at%. A four detector TDPAC apparatus can be found in (5,6). A satisfactory fit to the time spectra the diamagnetic impurity is taken into account,…”