Charge-density-wave transitions in the local-moment magnet Er5Ir4Si10

We report the observation of a new type of charge-density wave (CDW) in the large magnetic-moment rare-earth intermetallic compound, Er5Ir4Si10, which then orders magnetically at low temperatures. Single crystal x-ray diffrac tion shows the development of a ID incommensurate CDW at 155 K, which then locks into a purely commensurate state below 55 K. The well-localized Er3moments are antiferromagnetically ordered below 2.8 K. We observe very shar p anomalies in the specific heat at 145 and 2.8 K, signifying the bull; nat ure of these transitions. Our data suggest the coexistence of strongly coup led CDW with local-moment antiferromagnetism in Er5Ir4Si10.