Work was continued on analysis of structural characteristics of zinc oxide films (prepared by IITD). The results were further used for correlation with other material characteristics.

Prepared α-AL2O3 particles of sizes ≤ 20 μm for the certification and dissemination of CRM materials to calibrate powder X-ray diffraction equipment. The crystallinity of the material was improved by annealing at 1400 0C for 11 hrs. The XRD pattern was recorded with a step size of 0.0050/3 sec and specimen spinning speed of 30 rpm. The entire powder pattern shows that the material is well crystalline with FWHM of 0.0450 for the 113 diffraction peak.

Studied different size nano-magnetic particles to understand the change in the physical properties because large volume fraction of atoms occupy the grain boundary area. Synthesized nano particles were annealed in varying temperature. Crystallinity improves on increasing temperature 373K to 1173K for 2 hrs duration. The material remains single crystalline phase in all the temperature as shown in (Fig. 5.5).

A selective range temperature sensor has been developed using ferrofluid. The principal is based on sensing minute change in air volume due to temperature according to standard gas law (PV=nRT). The device consists of a closed container with very low friction ferrofluid bearing based piston which moves when the temperature changes inside the container. The coefficient of friction of the magnets motion is tremendously reduced using ferrofluid material.

Nano-crystalline magnetic alloy CoFe2 were developed and analyzed for its potential applications. X-ray diffraction peaks and intensity of nano alloy confirmed the stability of the particles. The core to surface ratio of particle is very large which creates negative pressure and forms a CoFe nano – alloy from the initially synthesized mixed ferrite. The particles size varies from 5 - 28 nm on changing the annealing temperature from 373 K to 1173K. On heating, the crystallite size as well as the saturation magnetization (Ms) increases from 20 emu g–1 to 110 emu g–1.

Preparation of zinc oxide nanoparticles and the study of their microstructure is of extreme importance for understanding their basic material properties. Nanocrystalline zinc oxide powder samples were prepared by wet-chemical method under different growth conditions.The synthesized powder samples were investigated for crystalline phase, microstructural, morphological and luminescent characteristics. Variations in size and shape of particles were obtained under different conditions.

Facilities for Characterization of Materials by XRD and XRF Techniques

Facilities for characterization of materials by XRD/XRF techniques were provided for almost all projects of NPL on development of materials and devices. More than 650 samples were received from various groups of NPL and outside organizations for structural characterization and elemental analysis.