Magnetic Properties of Mn‐doped SnO₂ Thin Films Prepared by the Sol–Gel Dip Coating Method for Dilute Magnetic Semiconductors

Abstract

Manganese‐doped tin oxide (SnO2:Mn) thin films were deposited on glass substrates by the sol–gel dip coating technique. The effect on structural, morphological, magnetic, electrical, and optical properties in the films with different Mn concentrations (0–5 mol%) were investigated. X‐ray diffraction patterns (XRD) showed the deterioration of crystallinity with increase in Mn‐doping concentration. Scanning electron microscopy (SEM) studies showed an inhibition of grain growth with an increase in Mn concentration. X ray photoelectron spectroscopy (XPS) revealed the presence of Sn4+ and Mn3+ in SnO2: Mn films. SnO2: Mn films show ferromagnetic and paramagnetic behavior. These SnO2:Mn films acquire n‐type conductivity for 0–3 mol% (SnO2 ‐ Sn0.97Mn0.03O2) ‐doping concentration and p type for 5 mol% Mn‐doping concentration(Sn0.95Mn0.05O2) in SnO2 films. An average transmittance of > 75% (in UV‐Vis region) was observed for all the SnO2:Mn films. Optical band gap energy of SnO2: Mn films were found to vary in the range 3.55 to 3.71 eV with the increase in Mn‐doping concentration. Photoluminescence (PL) spectra of the films exhibited an increase in the emission intensity with increase in Mn‐doping concentration which may be due to structural defects or luminescent centers, such as nanocrystals and defects in the SnO2. Such SnO2:Mn films with structural, magnetic and optical properties can be used as dilute magnetic semiconductors.

XANES, EXAFS, EPR, and First-Principles Modeling on Electronic Structure and Ferromagnetism in Mn Doped SnO2 Quantum Dots

“…The high pressure microwave technique was used for the synthesis of SnO 2 and Mn doped SnO 2 of different Mn doping concentration (2,4,6, and 10%). The stoichiometric solution was prepared by dissolving the required amount of SnCl 4 • 5H 2 O (Sigma-Aldrich), MnCl 2 •4H 2 O (Merck), and sodium dodecyl sulfate (Merck) in 200 mL of premixed ethanol and water (1:1).…”

“…Doping of transition metals in SnO 2 activates the spin polarization through sp–d exchange interactions between the host band structure electrons and the localized d electrons of transition metals . Among the various transition metals, Mn received considerable attention due to its large equilibrium solubility and nearly the same ionic radii (Mn 3+ ionic radius of 0.65 Å) as compared to Sn 4+ (ionic radius of 0.69 Å) for substitution. , Sabergharesou et. al investigated the local structure and magnetic properties of Mn doped SnO 2 and reported room-temperature ferromagnetism with a saturation magnetic moment of 0.27 μ B /Mn for nanocrystalline films containing a high fraction of Mn 2+ dopant .…”

A highly sensitive and room temperature ethanol gas sensor based on spray deposited Sb doped SnO2 thin films

“…A small deviation in the chemical composition was observed for all the films compared to the standard stoichiometric ratio of the SnO 2 system. 18,32 Slight deviations in the compositional balance of ATO films also resulted from slight variations in spray dynamics during aerosol spraying onto the substrate. Hence, Sb substitution significantly impacts the SnO 2 system by creating different defects, which can lead to a variation in the surface structural properties.…”

Hemin-Modified SnO2/Metglas Electrodes for the Simultaneous Electrochemical and Magnetoelastic Sensing of H2O2

“…It exhibited four emission bands in UV and visible regions centered around 378, 395, 437 and 470 nm. The 378 band is assigned to the recombination of donor-acceptor pairs [52]. Violet emission i.e., 395 and 437 nm are ascribed to the surface dangling bonds or oxygen vacancies and Sn interstitials [53].…”