No abstract

In this work a Mn doped magnetoelectric BiFeO 3 system is studied. Xray diffraction (XRD), scanning electron microscopy, energy dispersive xray analysis (EDX), Mössbauer spectroscopy at room and high temperatures, differential scanning calorimetry (DSC), high temperature magnetization, dielectric constant measurements and x-ray photoelectron spectroscopy (XPS) are used to characterize the samples. The XRD result shows BiFeO 3 as a major phase along with about 1-2% impurity phase. EDX shows the equi-atomic ratio of Bi and Fe site cations. Using DSC it is observed that the Néel temperature decreases with Mn doping. Using Mössbauer and XPS it is observed that Fe exists in the +3 oxidation state. The samples have an antiferromagnetic nature with Mn doping.

Thin films of magnetite (Fe 3 O 4 ) are grown on single crystal GaAs (100) substrate by pulsed laser deposition. X ray diffraction (XRD) result shows the (111) preferred orientation of the Fe 3 O 4 film and x-ray photoelectron spectroscopy confirm the presence of single phase Fe 3 O 4 in the film. The electrical transport property of the film shows the characteristic Verwey transition at 122 K and below 110 K, the transport follows variable range hopping type conduction mechanism. The film shows room temperature magnetization hysteresis loop suggesting the ferrimagnetic behavior of the film with saturation magnetization value close to 470 emu/cc. PACS Nos.: 75.50.Gg, 73.61.-r, 75.47.-m a Corresponding author e mail: dmphase@csr.ernet.in

No abstract

No abstract

No abstract

No abstract

No abstract