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☑ Superparamagentic Behaviour of MgFe2O4 Nano-ferrite

A. K. Srivastava, Nishant Mongia

Department of Physics, Lovely Professional University, Phagwara, (Punjab)- 144411, India

  • subtitlesGRAPHICAL ABSTRACT
  • subtitlesABSTRACT

    In the present work, magnesium ferrite (MgFe2O4) nanostructures are fabricated by sol-gel method. Structural studies are carried out using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The XRD patterns of MgFe2O4 show single-phase formation of FCC spinel structure. The average particle size of samples sintered at different temperatures (300-800°C) is controlled in the nano-range i.e. ~ 10 nm. The crystallinity shows increment with increasing sintering temperature. Formation of spinel structure is confirmed using FTIR. The magnetic measurements are made from M-H hysteresis loops traced at room temperature using vibrating sample magnetometer (VSM). It is found that ferrites in the nanoregime are found to behave as single domain. The low temperature (300°C) sintered ferrite has almost zero coercivity and retentivity which shows superparamagnetic behaviour of the as-prepared ferrite.

  • gamesKEYWORDS

    Ferrite; superparamagnetic; VSM.

  • library_booksHEIGHLIGHTS
    1. (i)The sol-gel method is efficient for synthesizing MgFe2O4 nanoparticles possessing unique spinel structure, superparamagnetic properties and enhanced magnetic properties.
    2. (ii)Apart from size of the particles, the behaviour of nanoferrites also depends upon preparation parameters.
    3. (iii)The samples are resulting in comparatively smaller magnetizations and coercivities as the sintering temperature is lowered.
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☑ Temperature Dependent Structural and Magnetic Behaviour of Zn0.5Ni0.5Fe2O4 Nano-ferrite via Citrate Method

A. K. Srivastava, Dikshu Bansal

Department of Physics, Lovely Professional University, Phagwara, (Punjab)- 144411, India

  • subtitlesGRAPHICAL ABSTRACT
  • subtitlesABSTRACT

    In the present work, magnetic nanoparticles of Zn0.5Ni0.5Fe2O4 ferrite were synthesized using citrate precursor method. These nanoparticles were sintered at different temperatures ranging from 3000C to 10000C. Structural studies were carried out with X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Single-phase formation of spinel structure with cubic symmetry has been confirmed from the XRD patterns. The particle size and distribution was further checked by transmission electron microscope (TEM).Formation of spinel structure was confirmed from the spectra of FTIR. The investigation shows the increase in particle size with the increase in annealing temperature. The M-H loop at room temperature has been traced using vibrating sample magnetometer (VSM). The absence of magnetic parameters such as remanent magnetization, coercivity, hysteresis of the M-H curve and non zero magnetic moments indicate the existence of superparamagnetism in the magnetic nanoparticles.

  • gamesKEYWORDS

    Ferrite; superparamagnetism; structural properties.

  • library_booksHEIGHLIGHTS
    1. (i) Zn0.5Ni0.5Fe2O4 ferrite is successfully synthesized by sol-gel method
    2. (ii)Superparamagnetic behaviour has been obsered in the synthesized ferrite.
    3. (iii)The grain size of the ferrite lie in nano range.
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☑ Influence of La-Mg on Optical-Dielectric and Magnetic Properties of Barium Hexaferrite

Talwinder Kaura, Riti Sethib, A. K. Srivastavaa*

aDepartment of Physics, Lovely Professional University, Phagwara, (Punjab)- 144411, India

b Department of Physics, Jamia Millia Islamia, Central University, New Delhi-110025 (INDIA)

*Email:srivastava_phy@yahoo.co.in

  • subtitlesGRAPHICAL ABSTRACT
  • subtitlesABSTRACT

    In the present study, Ba1-x Mgx LaxFe12-xO19 (x =0. 1, 0.2, 0.3, 0.4 and 0.5) hexaferrites are prepared by sol-gel auto combustion method and subsequent heat treatment from 5000C to 9000C. The crystal structure, grain size, optical properties, dielectric properties, thermal properties and magnetic properties are studied by means of X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet visible near infrared (UV-Vis-NIR), inductance capacitance resistance meter bridge (LCR meter) , thermo gravimetric analysis (TGA)/ differential thermal analysis (DTA)/differential scanning calorimeter (DSC) and vibrating sample magnetometer (VSM). XRD studies indicate that barium hexaferrite still maintained the hexagonal magneto-plumbite phase after substitution of La-Mg and calcination. DTA studies show that the formation of hexaferrite phase takes place nearly at 8000C. VSM analysis reveals an increase in saturation magnetization, coercivity, retentivity and anisotropy constants with increase in substituent

  • gamesKEYWORDS

    Magnetic materials; Magnetic properties; Microstructure; Optical properties; Dielectric properties; Fourier transform infrared spectroscopy (FTIR).

  • library_booksHEIGHLIGHTS
    1. (i)We report here the successful synthesis of La-Ma doped Barium hexaferrite using sol gel method.
    2. (ii)There is remarkable change in magnetic properties like retentivity, coercivity and saturation magnetization with temperature.
    3. (iii) Materials show normal ferrite behaviour and band gap increases with substituion.
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☑ On rgw-Homeomorphism in Topological Space

Sanjay Mishra

Department of Mathematics, Lovely Professional University, Phagwara, (Punjab)- 144411, India

Email:drsanjaymishra@redifmail.com

  • subtitlesABSTRACT

    In this paper, we first introduce new class of homeomorphism called regular generalized weakly homeomorphism (briefly rgw-homeomorphism) in topological space and after that we compare this new class of homeomorphism with recently introduced generalized form of homeomorphism. Moreover, we study algebraic properties of the family of rgw - homeomorphism in topological space.

  • gamesKEYWORDS

    rgw-homeomorphism; topological space.

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☑ Exact Complex Invariants in 3-D for Classical System

Jasvinder Singh Virdi1 and S. C. Mishra2

1Department of Physics, Lovely Professional University, Phagwara, Punjab, India
2Department of Physics, Kurukshetra University, Kurukshetra-136119, India

1Email:jpsvirdi@gmail.com

  • subtitlesABSTRACT

    Attempts are made to construct three-dimensional complex dynamical invariant by using Lie- algebraic method to study complex dynamical systems on the extended complex phase. Such invariants play an important role in the analysis of complex trajectories with regard to the calculation of semi-classical coherent state propagator in the path integral method.

  • gamesKEYWORDS

    Complex Hamiltonian; Exact complex invariant.

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