Chatterji Tapan, Zamponi Michaela, Wuttke Joachim
Institut Laue-Langevin, B.P. 156, 38042 Grenoble Cedex 9, France.
J Phys Condens Matter. 2019 Jan 16;31(2):025801. doi: 10.1088/1361-648X/aaeead. Epub 2018 Dec 5.
We have investigated the ferromagnetic phase transition of elemental Co by high-resolution neutron backscattering spectroscopy. We monitored the splitting of the nuclear levels by the hyperfine field at the Co nucleus. The energy of this hyperfine splitting is identified as the order parameter of the ferromagnetic phase transition. By measuring the temperature dependence of the energy we determined the critical exponent [Formula: see text] and the ferromagnetic Curie temperature of [Formula: see text] K. The present result of the critical exponent agrees better with the predicted value (0.367) of the three-dimensional Heisenberg model than that determined previously by nuclear magnetic resonance.
我们通过高分辨率中子背散射光谱研究了元素钴的铁磁相变。我们监测了钴原子核处超精细场对核能级的分裂。这种超精细分裂的能量被确定为铁磁相变的序参量。通过测量能量的温度依赖性，我们确定了临界指数[公式：见原文]以及铁磁居里温度为[公式：见原文]K。临界指数的当前结果与三维海森堡模型的预测值（0.367）比先前通过核磁共振确定的结果吻合得更好。
