Kinetic arrest of the first-order ferromagnetic-to-antiferromagnetic transition in Ce(Fe<SUB>0.96</SUB>Ru<SUB>0.04</SUB>)<SUB>2</SUB>: formation of a magnetic glass

We present the results of a dc magnetization and magnetic relaxation study showing the kinetic arrest of a first-order ferromagnetic-to-antiferromagnetic transition in Ce(Fe<SUB>0.96</SUB>Ru<SUB>0.04</SUB>)<SUB>2</SUB>, resulting from the viscous retardation of growth of the antiferromagnetic phase. This leads to the formation of a nonergodic glasslike magnetic state. The onset of the magnetic-glass transformation is tracked through the slowing down of the magnetization dynamics. This glassy state is formed with the assistance of an external magnetic field and this is distinctly different from the well-known spin-glass state