TY - JOUR
T1 - Neutron scattering study of magnetic ordering and excitations in the ternary rare-earth diborocarbide Ce11 B2 C2
AU - Nakanowatari, Isao
AU - Morinaga, Rei
AU - Onimaru, Takahiro
AU - Sato, Taku J.
PY - 2007/11/21
Y1 - 2007/11/21
N2 - Neutron scattering experiments have been performed on the ternary rare-earth diborocarbide Ce11 B2 C2. The powder-diffraction experiment confirms formation of a long-range magnetic order at TN =7.3 K, where a sinusoidally modulated structure is realized with the modulation vector q= [0.167 (3), 0.167 (3), 0.114 (3)]. Inelastic excitation spectra in the paramagnetic phase comprise significantly broad quasielastic and inelastic peaks centered at ω 0, 8, and 65 meV. Crystalline-electric-field (CEF) analysis satisfactorily reproduces the observed spectra, confirming their CEF origin. The broadness of the quasielastic peak indicates strong spin fluctuations due to coupling between localized 4f spins and conduction electrons in the paramagnetic phase. A prominent feature is suppression of the quasielastic fluctuations, and concomitant growth of a sharp inelastic peak in a low-energy region below TN. This suggests dissociation of the conduction and localized 4f electrons on ordering, and contrasts the presently observed incommensurate phase with spin-density-wave order frequently seen in heavy fermion compounds, such as Cex La1-x Ru2 Si2.
AB - Neutron scattering experiments have been performed on the ternary rare-earth diborocarbide Ce11 B2 C2. The powder-diffraction experiment confirms formation of a long-range magnetic order at TN =7.3 K, where a sinusoidally modulated structure is realized with the modulation vector q= [0.167 (3), 0.167 (3), 0.114 (3)]. Inelastic excitation spectra in the paramagnetic phase comprise significantly broad quasielastic and inelastic peaks centered at ω 0, 8, and 65 meV. Crystalline-electric-field (CEF) analysis satisfactorily reproduces the observed spectra, confirming their CEF origin. The broadness of the quasielastic peak indicates strong spin fluctuations due to coupling between localized 4f spins and conduction electrons in the paramagnetic phase. A prominent feature is suppression of the quasielastic fluctuations, and concomitant growth of a sharp inelastic peak in a low-energy region below TN. This suggests dissociation of the conduction and localized 4f electrons on ordering, and contrasts the presently observed incommensurate phase with spin-density-wave order frequently seen in heavy fermion compounds, such as Cex La1-x Ru2 Si2.
UR - http://www.scopus.com/inward/record.url?scp=36348960032&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=36348960032&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.76.184427
DO - 10.1103/PhysRevB.76.184427
M3 - Article
AN - SCOPUS:36348960032
VL - 76
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 18
M1 - 184427
ER -