Low-dimensional magnetism of spin-1/2 chain systems α- And β-TeVO ₄: A comparative study

We present a comparative study of the low-dimensional compounds α- and β-TeVO ₄. Our data clearly show that the change in the local coordination geometry of V ⁴⁺ ions comparing α- and β-TeVO ₄ leads to a drastic differences in the magnetic properties. Despite sharing the same crystal structure, the two compounds realize different magnetic exchange topologies. Both compounds exhibit a transition from ferro- to antiferromagnetic correlations with decreasing temperature. This effect however is driven by different mechanisms for both compounds. Additionally, a dimensional crossover is found in β-TeVO ₄.