High field and temperature dependent magnetisation measurements on some RE₂Co₁₇ single crystals

Single crystals of Pr₂CO₁₇ and Nd₂Co₁₇ have been grown using a tri-arc Czochralski method. High-field magnetization measurements up to 35 T have been performed on Pr₂Co₁₇ and Nd₂Co₁₇ at 4.2 K. The experimental curves show very large anisotropy; for fields along the c axis in Pr₂Co₁₇ and along the a axis in Nd₂Co₁₇ the magnetization does not reach the saturation value within this field range. Furthermore, the hard axis shows in both compounds a nonzero spontaneous magnetization indicating a cone structure with cone angles of about 26 degrees and 7 degrees for Pr₂Co₁₇ and Nd₂Co₁₇, respectively. Low-field (up to 6 T) temperature-dependent magnetization measurements (4.2-300 K) show that in both compounds the cone angle remains visible up to 300 K, but for Pr₂Co₁₇ the cone angle is drastically reduced above 150 K. These two RE₂TM₁₇ compounds (RE stands for a rare-earth metal and TM stands for a transition metal) with a cone structure are compared with other RE-TM compounds with a cone structure.