μSR investigation of CeCo4B

The preliminary results of our zero-field muon spin relaxation (μSR) experiments on a polycrystalline CeCo4B sample, at ambient pressure are reported. The onset of the magnetic transition at TC=293 K was evidenced by the critical-like behavior of the μSR rate above the transition temperature and the occurrence of an oscillating component in the μSR signal below TC. The frequency corresponding to the oscillating signal has a maximum around 150 K then it splits into two components below ∼120 K, the temperature (Tt) at which an isostructural transition was reported in the literature. Magnetic measurements in the temperature range of 4.2–850 K and external magnetic fields up to 9 T were also performed to characterize the bulk magnetic properties of CeCo4B, while from band structure calculations we were able to compute the values of the Ce and Co magnetic moments. We found arguments that at zero applied pressure the magnetic ordering in CeCo4B is ferrimagnetic and that the transition at Tt is accompanied by a reorientation of a sublattice magnetization.