ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
RE2CuO4 (RE=rare earth) compounds constitute an interesting family of materials because of their magnetic complexity as well as for their relationship with high Tc superconductors. For R=Gd and heavier rare earths, a weak ferromagnetic component (WF) is observed below ∼280 K. This component has its origin in a canting of the Cu antiferromagnetic (AF) structure due to a distortion of the oxygen ions between the copper atoms. In this contribution we center our work in Gd2CuO4, which is the only WF compound in the series that can be synthesized at normal pressures. WF can be easily detected by microwave absorption, due to the presence of an associated low field absorption signal. We have synthesized the material by sol-gel methods, allowing a control of grain size, dependent on time and the final calcination temperature. The microwave absorption results show that the onset point for the WF component shifts from 290 K for the bulk material, to 210 K for particles with an average size of 120 nm. For particles less than 90 nm the WF resonance line is not observed, suggesting the absence of weak ferromagnetism. As the WF component is associated to the AF ordering, we interpret our results as the elimination of the long range order motivated by the particle size reduction. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.361307
