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NiFe 2 O 4 /MWCNTs nanohybrids were synthesized via novel one step ultrasonication assisted method using ortho-xylene as a dispersive medium with varying MWCNTs concentration (0.0%, 1.0%, 1.5%, 2.0% and 2.5%). The nanohybrids were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Impedance Analyzer techniques. XRD indexed patterns confirmed the formation of NiFe 2 O 4 /MWCNTs nanohybrid. The SEM images showed the decoration of nickel ferrite nanoparticles on MWCNTs. The FTIR results show two absorption bands. The Cole-Cole plots of impedance show the resistance was only due to the grain boundary contribution. The dielectric properties were found to be increasing with increasing MWCNTs concentration. For 2.5% MWCNTs concentration, dielectric constant and loss 1.06×10 5 , 1.99×10 6 were achieved as compared to pure nickel ferrite 6.17×10 3 , 3.87×10 4 , respectively. Such increase in the dielectric properties renders its application at high frequency [ABSTRACT FROM AUTHOR]

The first 413-phase entropy-enhanced (Nb 0.8 Ti 0.05 Ta 0.05 V 0.05 M 0.05) 4 AlC 3 (M = Hf, Zr) (EEMAX Hf and EEMAX Zr) ceramics were successfully consolidated by spark plasma sintering (SPS) using Nb, Ti, Ta, V, Zr, Hf, Al and graphite as initial materials. The formation of solid solution with five transition metals at the M sites of hexagonal M 4 AlC 3 unit cell was confirmed by elemental analyses. Compared with pure Nb 4 AlC 3 , both the electrical and thermal conductivities of the entropy-enhanced ceramics showed a slight decrease, which is attributed to the lattice distortion and the increasing lattice defects that prevents the transfer of electrons and phonons. On the other hand, the mechanical properties of entropy-enhanced ceramics were greatly enhanced compared to pure Nb 4 AlC 3. The measured fracture toughness of EEMAX Hf and EEMAX Zr ceramics were 8.2 MPa·m1/2 and 10.0 MPa·m1/2, respectively, which were increased by 18.8% and 44.9% compared to Nb 4 AlC 3. The compressive strength of EEMAX Hf and EEMAX Zr ceramics were 987 MPa and 1187 MPa, respectively, being 92.0% and 130.9% higher than that of Nb 4 AlC 3 , respectively. EEMAX Hf and EEMAX Zr ceramics also possessed the higher Vickers hardness of 6.8 GPa and 7.4 GPa, respectively. [ABSTRACT FROM AUTHOR]

Abstract Nickel ferrite (NiFe 2 O 4) nanoparticles were first prepared by co-precipitation route and then they were combined with multiwall carbon nanotubes (MWCNTs) using ultra-sonication assisted method. A facile two-step method was used to synthesize NiFe 2 O 4 /MWCNTs nanohybrid as an anode material to modify the electrochemical performance of lithium-ion battery. For the first-time, Toluene was used as a dispersive/linkage medium for the synthesis of this nanohybrid material. The formation of inverse spinel cubic structure with no impurity was investigated by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The average particle size of spherical nanoparticles was found about 36 nm NiFe 2 O 4 nanoparticles were embedded on the surface of MWCNTs. This nanohybrid material showed high specific capacity (i.e. 1302 mAh/g) and better cyclic performance (i.e. 871 mAh/g) after 25 cycles at 0.2 C-rate. More importantly, this showed excellent rate capability (i.e. 631 mAh/g) even at high 5 C-rate and returned to the initial capacity at 0.2C by giving 97% columbic efficiency. [ABSTRACT FROM AUTHOR]