Structural Determination of Frustrated Double Perovskites Ba₂EuMoO₆ and Ba₂PrMoO₆

Geometric magnetic frustration occurs when magnetic order is inhibited by the arrangement of magnetic ions. In some materials with antiferromagnetic interactions, the moments are arranged in such a way that only certain interactions can be satisfied at once, and are said to be magnetically frustrated.

Double perovskites of composition A₂BB′O₆, with ’rock-salt’ order of magnetic B’ ions, potentially exhibit frustration. Double perovskites are of particular interest due to their chemical versatility, enabling the synthesis of compounds with divergent chemical and magnetic properties, providing great potential to yield new insights into frustration physics.

We have studied the structure of two double perovskites, Ba₂EuMoO₆ and Ba₂PrMoO₆, using X-ray diffraction. After encountering difficulties evidenced by peak splitting, a sample of Ba₂YMoO₆ was synthesized in order to test and refine the synthesis process. The Pr sample showed evidence of structural distortion while the Eu shows promise for future refinement.