Magnetic structure of the Kondo lattice compound CeZn$_{0.6}$Sb$_2$

The new Kondo lattice compound CeZn$_{0.6}$Sb$_2$ has a tetragonal structure with space group P4/nmm and shows ferromagnetic behavior below 2.5 K. The Curie-Weiss temperature is 22 K along the tetragonal $ab$ plane, indicating ferromagnetic interactions in the plane. Along the $c$ axis, however, the Curie-Weiss temperature is -145 K, suggesting antiferromagnetic exchange interaction in this direction [1]. We determined the magnetic structure of CeZn$_{0.6}$Sb$_2$ using single crystal neutron diffraction. ($h$,0,$l$) and ($h$,$h$,$l$) scattering planes were investigated. We found CeZn$_{0.6}$Sb$_2$ orders ferromagnetically at T$_C$=2.5 K. The magnetic structure is collinear with a low temperature ordered Ce moment of 1.3 (1) $\mu_B$ that lies in the $ab$ plane. In addition, we measured the order parameter of the ferromagnetic transition. [1] Studies of the ferromagnetic Kondo lattice system of single crystal CeZnSb$_2$, H. Lee, S. Nakatsuji, Y. Chen, W. Bao, R. Macaluso, J. Chan, T. Park, B. Carter, P. Klavins, J. Thompson, Z. Fisk, BAPS, Session L41, 2005.