Absence of ferromagnetism in Co and Mn substituted polycrystalline ZnO

Preparation and Characterization of Mn and Co substituted nanoparticle ZnO

With a view to investigate the influence of nano size on various physical properties of transition metal substituted ZnO, a series of materials were prepared by different chemical routes viz; Citrate gel, polyvinyl alcohol (PVA ) precursor and Chemical solution decomposition (CSD) methods. In the citrate gel method, the starting materials were nitrates and ethylene glycol acts as a gelating rea...

Dielectric relaxation of shallow donor in polycrystalline Mn-doped ZnO

The dielectric properties of Mn-doped ZnO ceramics with electrically active grain boundaries at low temperatures of 10–70 K were investigated by admittance spectroscopy. It was observed that the dielectric relaxation of the main shallow donors, zinc interstitial, in these samples occurred in the temperature range of 20–50 K. Based on theoretical analysis, an expression for the admittance of an ...

Ferromagnetism in sol-gel derived ZnO: Mn nanocrystalline thin films

This paper reports the growth of Mn doped ZnO thin films by sol-gel technique with different Mn concentration (0-20 %). Structural and vibrational properties have been measured by X-ray diffraction and Raman spectroscopy. The films exhibit crystalline nature with (002) preferential orientation. The crystallite size and lattice parameters have been estimated as a function of Mn concentration. Th...

Sample preparation and annealing effects on the ferromagnetism in Mn-doped ZnO

FERROMAGNETISM IN (Ga,Mn)As AND (Ga,Mn)N

(Ga,Mn)As and (Ga,Mn)N are so called diluted magnetic semiconductors, i.e. semiconductor based materials made ferromagnetic by inclusion of a magnetic element—in this case Mn. This type of materials bridge over the incompatibilities in metal–semiconductor interfaces in electronics components and have an enormous potential for future spintronics applications, where both charge and spin degrees o...