Abstract
The magnetic properties of the pseudobinary Zr(Fe1-xCox)2 system were studied by magnetic, Mossbauer and low-temperature specific heat measurements. ZrFe2 is a strong ferromagnet, whereas ZrCo2 shows Pauli paramagnetism. Both the spontaneous magnetisation and the Curie temperature decrease with increasing Co content and the system becomes a weak ferromagnet for x=0.3 and 0.4, where remarkable Invar anomalies are observed. In x=0.5 approximately 0.7, the system shows micromagnetism. No spin freezing has been detected down to 4.2K for x-0.8 approximately 1.0. It has been shown that ferromagnetism is markedly enhanced by excess Fe and Co atoms which occupy Zr sites.