We present here the magnetic properties of ternary intermetallic compound UCuGe1.025, a Ge-rich UCuGe system with hexagonal CeCd2-type crystal structure (space group P3m1). Dc magnetization and ac susceptibility measurements reveal that UCuGe1.025 is dominated by long-range ferromagnetic interactions with Curie temperature Tc=70 K. Irreversible magnetism observed in this system is mainly resulted from the domain-wall pinning effects due to strong magnetic anisotropy. A very small frequency shift of ac susceptibility peak position is observed suggesting that some spins are randomly frozen in this system in spite of the rather weak spin-glass effect. Our data are also compared with other reported experimental results of the Ge-deficient and stoichiometric UCuGe systems. It is concluded that in U-Cu-Ge systems antiferromagnetic exchange interaction is weakened and ferromagnetic interaction is strengthened with increasing Ge-concentration in the vicinity of the composition 1:1:1.
- Domain-wall pinning effect
- Spin glass