Anomalous change of the magnetic moment direction by hole doping in CeRu${}_2$Al${}_{10}$

Abstract

We present a detailed investigation of the hole (3\% Re) doping effect on the polycrystalline CeRu${}_2$Al${}_{10}$ sample by magnetization, heat capacity, resistivity, muon spin rotation ($\mu$SR), and neutron scattering (both elastic and inelastic) measurements. CeRu${}_2$Al${}_{10}$ is an exceptional cerium compound with an unusually high Neel temperature of 27 K. Here we study the stability of the unusual magnetic order by means of controlled doping, and we uncover further surprising attributes of this phase transition. The heat capacity, resistivity and $\mu$SR measurements reveal an onset of magnetic ordering below 23 K, while a broad peak at 31 K (i.e. above $T_N$), has been observed in the temperature dependent susceptibility, indicating an opening of a spin gap above $T_N$. Our important finding, from the neutron diffraction, is that the compound orders antiferromagnetically with a propagation vector $\mathbf{k}$ = (1 0 0) and the ordered state moment is 0.20(1)${\mu }_B$ along the $b-$axis. This is in sharp contrast to the undoped compound, which shows AFM ordering at 27 K with the ordered moment of 0.39(3)${\mu }_B$ along the $c-$axis. Similar to CeRu${}_2$Al${}_{10}$ our inelastic neutron scattering study on the Re doped shows a sharp spin gap-type excitation near 8 meV at 5 K, but with slightly reduced intensity compared to the undoped compound. Further the excitation broadens and shifts to lower energy ($\le$ 4 meV) near 35 K. These results suggest that the low temperature magnetic properties of the hole doped sample is governed by the competition between the anisotropic hybridization effect and crystal field anisotropy as observed in hole-doped CeOs${}_2$Al${}_{10}$.

arXiv comment10 pages, 10 figures, Submitted to Phys. Rev. B

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Cited by in corpus (6)

• Understanding the magnetism in noncentrosymmetric CeIrGe3: Muon spin relaxation and neutron scattering studies
• Contrasting electron and hole doping effects on the spin gap of the caged type Kondo semimetal CeOs${}_2$Al${}_{10}$: A muon spin relaxation and inelastic neutron scattering investigation
• Contrasting chemical pressure effect on the moment direction in the Kondo semiconductor CeT${}_2$Al${}_{10}$ (T = Ru,Os)
• Incommensurate-Commensurate Magnetic Phase Transition in SmRu${}_2$Al${}_{10}$
• Effect of Nd and Rh substitution on the spin dynamics of Kondo insulator CeFe2Al10
• Tuning the hybridization and magnetic ground state of electron and hole doped CeOs${}_2$Al${}_{10}$: an x-ray spectroscopy study