An experimental study on the influence of planar anisotropy on the critical behavior of a Fe17Dy2 single crystal

In order to check the influence of planar anisotropy on the magnetic phase transition which occurs at the Curie temperature, we have made a detailed e xperimental study on the critical behavior of a high quality Fe17Dy2 single crystal which has a strong planar anisotropy. This study includes deducing various critical exponents from extensive magnetization measurements. The asymptotic and effective critical exponents and their corresponding amplitu des have been derived from the magnetization data measured with the applied field along the easy plane using the conventional methods to analyze phase transitions with and without the inclusion of the "correction-to-scaling'' terms originating from the nonlinear irrelevant scaling fields. Inclusion of the correction-to-scaling terms could only influence the critical amplit ude values. The values of the critical exponents obtained in this way are f ound to be in excellent agreement with those obtained from the magnetizatio n data taken with the applied field parallel to the hard axis, indicating t hat the planar anisotropy has not influenced the critical behavior. These r esults are in agreement with the observations made on Fe17Ho2 and Fe17Er2 s ingle crystals. (C) 1999 American Institute of Physics. [S0021-8979(99)7620 8-0].