3d transition metal doped Zn sub(0.95)Tm sub(005)O (Tm = Mn, Co, Ni, Cu): structure, microstructure, Raman, dielectric constant and magnetism

• Published in: Materials research express 2015-10, Vol.2 (10), p.1-10
• Main Authors: Varshney, Dinesh, Dwivedi, Sonam
• Format: Article
• Language: English
• Subjects: Cobalt; Copper; Manganese; Microstructure; Nickel; Three dimensional; Transition metals; Zinc oxide
• ISSN: 2053-1591; 2053-1591
• DOI: 10.1088/2053-1591/2/10/106102

We present the structural, microstructural, optical, dielectric, and magnetic behavior of 3d transition metal (Tm) doped Zn sub(0.95)Tm sub(0.05)O (Tm - Mn, Co, Ni, Cu) diluted magnetic semiconducting samples as synthesized by solid-state route reaction method. X-ray diffraction (XRD) pattern infers that the sample of Zn sub(0.95)TM sub(0.05)O (Tm - Mn, Co, Ni, Cu) is in single-phase wurtzite structure (hexagonal phase, P6 sub(3)mc). The average particle size obtained for different compositions of Zn sub(0.95)TM sub(0.05)O (TM = Mn, Co, Ni, Cu) are 0.499, 0.517, 0.568, and 0.572 [mu]m, respectively. Ni-doped ZnO has obtained the lowest band gap (~3.1 eV) as compared to other transition metal (Tm = Mn, Co, Cu) ion-doped ZnO. The effect of Tm ions substitution on dielectric constant, and loss tangent, is also studied at room temperature in a wide range of frequencies between 50 Hz-1 MHz. The dielectric parameters were enhanced by the replacement of Zn ions with transition metal ions. Room temperature magnetization-magnetic field (M-H) measurements show the paramagnetic behavior of Zn sub(0.95)Mn sub(0.05)O and Zn sub(0.95)Cu sub(0.05)O, diamagnetic characteristic of Zn sub(0.95)Co sub(0.05)O, and ferromagnetic response of Zn sub(0.95)Ni sub(0.05)O. In Zn sub(0.95)Ni sub(0.05)O samples the saturation occurs at 2 kOe, while the small value of coercive field is about 100 Oe at room temperature and is attributed to the soft nature of Zn sub(0.95)Ni sub(0.05)O.