Structure and magnetic properties of new Be-substituted langasites A3Ga3Ge2BeO14 (A=Pr, Nd, and Sm)

Langasites have been studied extensively in past for their functional properties and use in telecommunication. A thorough understanding of their ground state is limited by the difficulty in synthesizing new members belonging to this series due to the formation of competing phases such as the garnets. Three magnetic langasites A3Ga3Ge2BeO14 (A=Pr, Nd, and Sm) and a non-magnetic lattice standard La3Ga3Ge2BeO14 were synthesized using the ceramic method. These were further characterized by X-ray diffraction, magnetization, magnetic susceptibility and heat capacity measurements. All three langasites exhibit net antiferromagnetic interactions at low temperatures and no evidence of long range magnetic ordering was observed down to 0.350K.