A Review of EPR Studies on Magnetization of Nanoparticles of Dilute Magnetic Semiconductors Doped by Transition-Metal Ions

2015 ◽  
Vol 46 (6) ◽  
pp. 693-707 ◽  
Author(s):  
Sergey I. Andronenko ◽  
Sushil K. Misra
2013 ◽  
Vol 201 ◽  
pp. 103-129 ◽  
Author(s):  
Tokeer Ahmad ◽  
Sarvari Khatoon ◽  
Ruby Phul

Nanomaterials have fascinated researchers in recent years because these materials exhibit unusual optical, magnetic and electrical properties as compared to their bulk counterparts. Incorporating impurity ions into a semiconducting host to extend its properties has been one of the most important techniques that paved the way for the modern technology based on spintronic devices. Over the past few years, oxide based dilute magnetic semiconductors (DMSs) have gained remarkable interest due to the possibility of inducing room temperature ferromagnetism. This review describes the experimental developments and optical properties of oxide based DMSs, including the recent results on ZnO, CdO and In2O3 based systems. Optical properties of transition metal (TM)-doped ZnO, CdO and In2O3 dilute magnetic semiconductor nanoparticles show red shift in energy band gaps. Such types of phenomena are attributed to sp-d exchange interactions between band electrons and localized d-electrons of the substituted transition metal ions. Table of Contents


Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.


Author(s):  
Mohammed Al-Amery1 ◽  
Ashraf Saad Rasheed ◽  
Dina A. Najeeb

Five new mixed ligand metal complexes have been synthesized by the reaction of divalent transition metal ions (Hg, Ni, Zn, Cu and Cd) with 2-(naphthalen-l-ylamino)-2-phenylacetonitrile (L1 ) and 1,10-phenanthroline (L2). The coordination likelihood of the two ligands toward metal ions has been suggested in the light of elemental analysis, UV-Vis spectra, FTIR, 1H-NMR, flam atomic absorption, molar conductance and magnetic studies. Results data suggest that the octahedral geometry for all the prepared complexes. Antibacterial examination of synthesized complexes in vitro was performed against four bacterias. Firstly, Gram-negative bacteria namely, Pseudomonas aerugin and Escherichia. Secondly, Gram-positive bacteria namely, Bacillus subtilis, Staphylococcuaurouss. Results data exhibit that the synthesized complexes exhibited more biological activity than tetracycline pharmaceutical.


Author(s):  
Olivier Charles Gagné ◽  
Frank Christopher Hawthorne

Bond-length distributions are examined for thirty-three configurations of the metalloid ions and fifty-six configurations of the post-transition-metal ions bonded to oxygen. Lone-pair stereoactivity is discussed.


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