Antiferromagnetic resonance of polycrystalline BiMn2O5

• Synthesis of pollycrystaline samples of multiferroic BiMn2O5 is described.
• High magnetic field multi-frequency EPR results are identified as AFMR.
• Yosida and Nagamiya theory of AFMR is used to find the AFMR modes.
• High values of macroscopic anisotropy constants are found from the data.
• Single site anisotropy microscopic constant is estimated.

Multi-frequency electron spin resonance (ESR) measurements in polycrystalline samples of BiMn2O5 were employed to observe antiferromagnetic resonances (AFMR) in the range 0–14 T below the Néel temperature. The experimental data were analyzed using the phenomenological theory of Yosida and Nagamiya. Three resonance modes were identified in the xz (ac) plane from the data at 5 K. Macroscopic constants of anisotropy K1=12.5×106 erg/cm3 and K2=7.0×106 erg/cm3 were calculated allowing for the single-site anisotropy constant K′ to be estimated at T=0 K. The obtained value shows reasonable agreement with theoretical predictions.