Muon Spin Relaxation Study of an Impurity Doped Antiferromagnetic Triangular Lattice with a 1D Ferromagnetic Chain: Ca_(3)(Co_(1-x)Zn_(x))_(2)O_(6)

摘要

Measurements of magnetization and muon spin relaxation ((mu)SR) have been carried out for the sample of Ca_(3)(Co_(1-x)Zn_(x))_(2)O_(6) with a frustrated antiferromagnetic triangular lattice consisting of Ising ferromagnetic chains for the purpose of the investigation of Zn-substitution effect on the frustrated system. The magnetic ordering temperature T_(c1) determined from magnetization data is 22 K for x velence 0.03, which is 3 K lower than that of the un-doped sample. This implies the reduction of an inter-chain interaction due to Zn-substitution. In the (mu)SR measurement in longitudinal fields, static magnetic order could not be observed even at 18 K below T_(c1). By Zn-substitution up to 3 percent in Ca_(3)Co_(2)O_(6), the magnetic frustration is not removed but rather enhanced due to the reduction of the exchange interaction in nearest and next nearest neighbors.