Magnetic properties of two new compounds: Pr/sub 2/Ni/sub 3/Si/sub 5/ and Ho/sub 2/Ni/sub 3/Si/sub 3/

Formation of two more new materials, Pr/sub 2/Ni/sub 3/Si/sub 5/ and Ho/sub 2/Ni/sub 3/Si/sub 5/, of the series, R/sub 2/Ni/sub 3/Si/sub 5/ (R=rare earth and Y) and their magnetic properties are reported here. These materials crystallize in the orthorhombic U/sub 2/Co/sub 3/Si/sub 5/-type structure (space group Ibam). Magnetic susceptibility measurement in the temperature range 5 K-300 K show that the compound Pr/sub 2/Ni/sub 3/Si/sub 5/ orders antiferromagnetically at T/sub N//spl sim/8.5 K and Ho/sub 2/Ni/sub 3/Si/sub 5/ at /spl sim/6 K. Considering T/sub N/(Gd/sub 2/Ni/sub 3/Si/sub 5/) /spl sim/15 K, T/sub N/(Pr/sub 2/Ni/sub 3/Si/sub 5/) /spl sim/ 8.5 K is rather high. The magnetic susceptibility of both of the materials, in the paramagnetic state, follows a Curie-Weiss law with effective moment close to that of the corresponding free trivalent rare earth ion.<
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