The magnetostriction of the intermetallic compound ErCo_2 near the magnetic phase transition paramagnetism- ferrimagnetism

摘要

The purpose of this work was the investigation of magnetostriction near magnetic phase transition paramagnetism-ferrimagnetism in ferrimagnetic intermetallic compound ErCo_2. It is known that 3d-electrons are delocalized and form a 3d-zone in it, whereas 4f-electrons localized and create an effective exchange field which acts on the Co sublattice. It leads to magnetic ordering of the last. We have found there is a sharp jump in the curve of thermal expansion near T = 37K, which indicates the presence of first order phase transition. Volume magnetostriction ω reach huge values (3.10~(-3) in the field μ_0H = 4T near T_c). At temperatures T > T_c λ_(||) and λ_⊥ have small values in the absence of an external magnetic field. However, in fields H>H_(crit) λ_(||) and λ_⊥ rapidly increase and get the values that have the same order of magnitude as at T?TC. This indicates that the external magnetic field can restore the magnetism of 3d-subsystem at T>T_C.