Elastic behaviour of microwave hydrothermally synthesized nanocrystalline Mn1−x–Znx ferrites

Microwave-hydrothermal (M-H) method has been successfully used for synthesis of nanocrystalline Mn–Zn ferrites which are used for high frequency applications. The nanopowders were characterized using XRD and TEM. The particle size of the samples varies from ∼20 nm to 25 nm. The powders were densified at 900 °C/30 min using microwave sintering method. The sintered ferrite samples were characterized using XRD, X-ray photoelectron spectroscopy (XPS), SEM and energy dispersive X-ray spectroscopy (EDS). The elastic behaviour and internal friction studies were carried out using composite piezoelectric oscillator method in the temperature range of 300–600 K. It was found that the anomalous behaviour observed in the temperature dependence of Youngʹs modulus and internal friction disappears with the application of a magnetic field equal to the saturation field (900 mT) of the specimen under investigation. The observed anomalous behaviour in the vicinity of the Curie temperature was understood with the help of Landauʹs theory.