Presence of a Spin Glass State in Antiferromagnetic Tb2CuIn3
Evidence of the coexistence of an ordered antiferromagnetic and a spin glass state is given by studying a polycrystalline Tb2CuIn3 sample with neutron diffraction in a non-magnetic and a magnetic environment. Tb2CuIn3 is an antiferromagnet with competing exchange interactions (J1> 0 for nearest neighbours and J2 < 0 for next nearest neighbours) and an ordering temperature TN =33 ± 1 K. Powder diffraction measurements reveal a broad diffuse peak - due to short-range magnetic order - underneath the (100) long-range order magnetic Bragg reflection. The exposure of the sample in magnetic fields up to 7.5 T, under both zero field and field-cooled conditions, show that neither the long-range magnetic order nor the short-range order are destroyed by the outer magnetic fields. The almost field independent behaviour of the magnetic intensities is explained by the existence of a spin glass state. Support on the simultaneous presence of antiferromagnetic and spin glass states is given by recent ac-dc magnetic measurements. The infinite range model for spin glasses with strong uniaxial anisotropy has predicted this kind of magnetic behaviour.
Yvonne Andersson, Eric J. Mittemeijer and Udo Welzel
I.M. Siouris et al., "Presence of a Spin Glass State in Antiferromagnetic Tb2CuIn3 ", Materials Science Forum, Vols. 443-444, pp. 391-396, 2004