Structural, optical and magnetic properties of Sm doped ZnO at dilute concentrations

Abstract

The work is important for the development of semiconductor devices which may create new dimensionality to control and achieve high temperature ferromagnetism.

Structural and optical characterization of Sm-doped ZnO nanoparticles

“…Pandiyarajan et al [26] reported a lattice expansion with Sm-doping. The observed shift in the peak positions towards higher angles, however, did not continue with an increase in the doping level of Sm, i.e., no further lattice contraction is observed within error with doping concentration of 2 and 4%, which is in excellent agreement with the previously reported studies [24,31]. This trend can be tentatively attributed to a further increase in the concentration of defects and impure atoms due to the increased substitutional doping of Sm and size mismatch between the ions present in the structure.…”

“…One expects to observe a lattice expansion rather than a contraction due to the substitution of bigger Sm 3+ (0.964 nm) for Zn 2+ (0.74 nm); however, this strongly depends on the presence of the lattice distortion and strain and defects induced by the slight substitution of Sm 3+ . For instance, while Arora et al [31] and Kumar et al [24] found a slight lattice contraction upon Sm doping. Pandiyarajan et al [26] reported a lattice expansion with Sm-doping.…”

Effect of dilute concentrations of Sm on the temperature‐dependent electrical and dielectric properties of ZnO

“…For x = 0.02 and x = 0.03 the plots show 2 straight lines with lower temperature activation energies being equal to 0.41 and 0.25 eV which corresponds to oxygen vacancies V o and Zn 2+ or Zn i with respect to high‐temperature activation energy which lies between 1.41 and 1.16 eV. A reduction in the PL intensity which is due to the reduction in zinc interstitials (Zn i ) and oxygen vacancies (V o ) for x = 0.01 clearly explains this low value of activation energy as compared to x = 0.02 and x = 0.03. It may also be noted that dc activation energy increases above x = 0.02.…”

“…Zn ions when substitutionally doped by rare earth (RE) or transition‐metal (TM) ions makes ZnO among the promising materials in the field of spintronics . It possesses optoelectronic applications, such as UV laser diode, light‐emitting diode, and photonics.…”

“…Zn ions when substitutionally doped by rare earth (RE) or transition-metal (TM) ions makes ZnO among the promising materials in the field of spintronics. [1][2][3][4][5][6] It possesses optoelectronic applications, such as UV laser diode, lightemitting diode, and photonics. It has high excitonic binding energy (60 meV) and this energy is a function of the dielectric constant of the material.…”