Hafnium oxide and Hafnium oxynitrides thin films are deposited on a Si substrate using reactive sputtering. Compared with Hafnium dioxide, Hafnium oxynitrides showed excellent electrical characteristics such as low leakage current density and low capacitance equivalent oxide thickness. By X-ray photoelectron spectroscopy (XPS), we were able to confirm nitrogen incorporation in the oxide bulk an...

The paper will introduce a simple new method on the synthesis of both hafnium and zirconium nitrate precursors. The intermediate product, dinitrogen pentoxide produced from the water extraction from fume nitric acid via phosphorus pentoxide, was condensed by liquid nitrogen trap into a flask equipped with hafnium or zirconium tetrachloride. To give the high yield, the mixture of fume nitric aci...

High-density metals such as hafnium and zirconium are of interest to the propellant, explosive, and pyrotechnic industry due to their high oxidation enthalpies; however, these metal fuels suffer from electrostatic discharge (ESD) complications creating safety concerns. Previous attempts to passivate these powders have failed due to abrasion of the protective coatings. Two novel methods for dese...

Immobilization of biomolecular probes to the sensing substrate is a critical step for biosensor fabrication. In this work we investigated the phosphate-dependent, oriented immobilization of DNA to hafnium dioxide surfaces for biosensing applications. Phosphate-dependent immobilization was confirmed on a wide range of hafnium oxide surfaces; however, a second interaction mode was observed on mon...

Time-differential perturbed angular correlation (TDPAC) studies in hafnium metal (∼ 5%Zr) have been carried out at different temperatures. It is found that hafnium metal on heating at 873 K continuously for two days in air, transforms partially and abruptly to HfO2 while no component of oxide has been observed for heating up to 773 K and during initial heating at 873 K for 1 day. This result is...

Three samples with dielectric layers from high- κ dielectrics, hafnium oxide, gadolinium-silicon oxide, and lanthanum-lutetium oxide on silicon substrate were studied by Raman spectroscopy. The results obtained for high- κ dielectrics were compared with spectra recorded for silicon dioxide. Raman spectra suggest the similarity of gadolinium-silicon oxide and lanthanum-lutetium oxide to the bulk...

Hafnium has been suggested as an interesting material for biomedical applications due to its good biocompatibility and osteogenesis. However, its behaviour under fretting corrosion conditions, found in applications such as dental and joint implants, has not been studied in depth. A three-electrode electrochemical cell integrated with a ball-on-flat reciprocating tribometer was used to investiga...

The use of liquid-liquid extraction for the separation of zirconium from hafnium was demonstrated. Hafnium spectrographically free of zirconium was prepared in quantity on a continuous basis. High purity fractions of zirconium were also prepared.

The semiconductor industry’s rapid development has been predicted by Moore’s law which states that the number of transistors on a silicon chip doubles every 18 months. The demand for high performance at a low cost has translated into downscaling of metal oxide semiconductor field effect transistor (MOSFET) devices resulting in shrinking of SiO2 gate oxide layer. At the present sub nanometer thi...

A 0.5 μm thick layer of rhodium was deposited on the CMSX 4 superalloy by the electroplating method. The rhodium-coated superalloy was hafnized and aluminized or only aluminized using the Chemical vapour deposition method. A comparison was made of the microstructure, phase composition, and oxidation resistance of three aluminide coatings: nonmodified (a), rhodium-modified (b), and rhodiumand ha...