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We have fabricated ZnFe xS (, 0.02, 0.04, 0.06, 0.08 and 0.10) diluted magnetic semiconductors using co-precipitation method. X-ray diffraction patterns depict that ZnFe xS appears as a dominant phase with cubic zinc blende structure and nanoscale crystallite size. In addition, a secondary phase of rhombohedral ZnS also appears; however, no additional phase arises that primarily belongs to Fe dopant. Using Debye-Scherrer relation, the crystallite size is found to be in the range of 20-27nm, which is in good agreement with the crystallite size calculated using the Williamson-Hall (WH) plot method. The appearance of secondary phase provoked to study the residual strain using Stokes-Wilson equation, which is nearly consistent to that observed using WH plot method. The surface morphology, revealed using scanning electron microscopy, depicts non-uniform surface structure with a variety of grains and void dimensions. Hysteresis loops measured for ZnFe xS at room temperature (RT) illustrate a paramagnetic behavior at higher fields; however, small ferromagnetic behavior is evident due to the small openings of the measured hysteresis loops around the origin. The measured RT ferromagnetism reveals the potential spintronic device applications of the studied diluted magnetic semiconductors. [ABSTRACT FROM AUTHOR]

Abstract Rare earth Dy3+ and divalent Mn2+ elements substituting W-type hexagonal ferrites Ba 1−x Dy x Zn 2 Fe 16−y Mn y O 27 (x = 0, 0.02, 0.06, 0.1 and y = 0, 0.1, 0.3, 0.5) were prepared by sol-gel method. The thermo- gravimetric analysis (TGA) and differential scanning calorimetry (DSC) was carried out to find the temperature at which single phase can be obtained. XRD patterns indicate the presence of the single phase for all the synthesized samples with the absence of any extra peak due to unreacted material and secondary phases. The occurrence of absorption bands at low wave numbers (563 and 446 cm−1), can be assigned to the stretching vibration of metal and oxygen ions in FTIR spectra, which also confirms the single hexagonal phase for prepared material. The grains are of platelet like structure, which enhances the microwave absorption properties of hexagonal ferrites. The synthesized material exhibits the minimum reflection loss of −20.9 dB at 11.8 GHz frequency, which reflects the applications of this material in super high frequency devices. The microwave conductivity of the material increases with frequency. [ABSTRACT FROM AUTHOR]