TY - JOUR
T1 - Antiferromagnetic order in the honeycomb Kondo lattice CePt6Al3 induced by Pd substitution
AU - Oishi, R.
AU - Umeo, K.
AU - Shimura, Y.
AU - Onimaru, T.
AU - Strydom, A. M.
AU - Takabatake, T.
N1 - Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/9/1
Y1 - 2021/9/1
N2 - The cerium-based compound CePt6Al3, in which Ce atoms form a honeycomb lattice hosting magnetic frustration, has a heavy-fermion ground state. We have observed development of magnetic order in partially Pd-substituted Ce(Pt1-xPdx)6Al3 series up to x = 0.3 by the measurements of magnetic susceptibility, electrical resistivity ρ, and specific heat C. In the whole range of x, the unit cell volume remains unchanged within 0.2%, and the effective magnetic moment stays at 2.4μB/Ce. For x = 0.05, both C/T and ρ(T) jump on cooling at Tm=1.8K. With increasing x to 0.2, Tm increases to 3.8 K, where C/T shows a pronounced λ-type anomaly. Application of magnetic fields suppresses Tm, which is indicative of an antiferromagnetic (AFM) ordered state. Thus, a long-range AFM order is induced by the substitution of isovalent Pd for Pt in CePt6Al3 without carrier doping and chemical pressure. We attribute the emergence of AFM order in Ce(Pt1-xPdx)6Al3 to the randomness in the spin-orbit interaction in the Pt-Pd sublattice, which weakens both the coherent Kondo effect and magnetic frustration in the honeycomb Kondo lattice.
AB - The cerium-based compound CePt6Al3, in which Ce atoms form a honeycomb lattice hosting magnetic frustration, has a heavy-fermion ground state. We have observed development of magnetic order in partially Pd-substituted Ce(Pt1-xPdx)6Al3 series up to x = 0.3 by the measurements of magnetic susceptibility, electrical resistivity ρ, and specific heat C. In the whole range of x, the unit cell volume remains unchanged within 0.2%, and the effective magnetic moment stays at 2.4μB/Ce. For x = 0.05, both C/T and ρ(T) jump on cooling at Tm=1.8K. With increasing x to 0.2, Tm increases to 3.8 K, where C/T shows a pronounced λ-type anomaly. Application of magnetic fields suppresses Tm, which is indicative of an antiferromagnetic (AFM) ordered state. Thus, a long-range AFM order is induced by the substitution of isovalent Pd for Pt in CePt6Al3 without carrier doping and chemical pressure. We attribute the emergence of AFM order in Ce(Pt1-xPdx)6Al3 to the randomness in the spin-orbit interaction in the Pt-Pd sublattice, which weakens both the coherent Kondo effect and magnetic frustration in the honeycomb Kondo lattice.
UR - http://www.scopus.com/inward/record.url?scp=85114494204&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.104.104411
DO - 10.1103/PhysRevB.104.104411
M3 - Article
AN - SCOPUS:85114494204
SN - 2469-9950
VL - 104
JO - Physical Review B
JF - Physical Review B
IS - 10
M1 - 104411
ER -