Crystal structures and magnetic properties of iron borates containing lanthanides Sr6LnFe(BO3)6 (Ln = La, Pr, Nd, SmLu)

• The iron borates containing lanthanides Sr6LnFe(BO3)6 (Ln = La, Pr, Nd, SmLu) were synthesized.
• All compounds have a disordered arrangement between Sr and Ln sites.
• From the magnetic susceptibility measurements, all compounds show a paramagnetic behavior.
• At very low temperatures (∼3 K), an onset of antiferromagnetic transition is observed in the specific heat measurements.

The crystal structures and magnetic properties of borate compounds Sr6LnFe(BO3)6 (Ln = La, Pr, Nd, SmLu) were investigated. These compounds crystallize in a hexagonal structure with space group R  3¯, in which the Ln and Fe ions form one-dimensional chain structure. From the results of structural analysis, it was found that there is an anti-site disorder between Sr and Ln sites, and its chemical formula can be represented as (Sr6–xLnx)(Ln1–xSrx)Fe(BO3)6. The value of x increases with ionic radius of Ln3+. The results of magnetic susceptibility measurements show that all the Sr6LnFe(BO3)6 are paramagnetic, and the onset of an antiferromagnetic ordering was observed below ∼3 K from the specific heat measurements.

Crystal structures and magnetic properties of iron borates containing lanthanides Sr6LnFe(BO3)6 (Ln = La, Pr, Nd, SmLu) were investigated. In these compounds, the Ln and Fe ions form one-dimensional chain structure along the c axis. We found that an anti-site disorder occurs between Sr and Ln sites and that the exact chemical formula should be represented as (Sr6–xLnx)(Ln1–xSrx)Fe(BO3)6. All these compounds are paramagnetic down to 1.8 K; however, the onset of an antiferromagnetic ordering was observed at very low temperatures from the specific heat measurements.Figure optionsDownload as PowerPoint slide