Abstract
Abstract
We report the synthesis, crystal structure, magnetization and specific heat studies of YCo3(OH)6.55Br2.45 single crystal. YCo3(OH)6.55Br2.45 crystallizes in trigonal structure, in which Co2+ ions form a perfect kagomé lattice. The magnetic susceptibility reveals successive magnetic transitions at 6.5 and 7.8 K and the Curie–Weiss fitting demonstrates that YCo3(OH)6.55Br2.45 has strong antiferromagnetic coupling and pronounced magnetic frustration effect. Specific heat data suggest that low-T magnetic transitions are attributed to antiferromagnetic ordering of Co2+ ions and the magnetic entropy points to effective 1/2 spin in the system. These results indicate that an unusual magnetic ordering state with effective spin-1/2 is realized in kagomé lattice system YCo3(OH)6.55Br2.45.