In this paper, we discuss a newly characterized compound, ZrW2Og, that has been introduced into the composite materials with an adjustable and low thermal expansion for electronic applications. Offering a negative coefficient of thermal expansion (CTE) of approximate ‐9xlO–6/°C in a large temperature range, ZrW2Og was used as a particle filler in polymer‐matrix composites. The paper presents two kinds of composites, that is, polyester and epoxy with various volume fractions of ZrW20g. The CTEs of the polyester/ZrW2Og and epoxy/ZrW2Og composites have been proven adjustable in the ranges of 94 to 56x10–6 /°C and 54 to 18х 10–6 /°C, respectively, with ZrW2Og filler from 0 to 30 vol%. In addition, the analysis about the interfaces between the matrices and filler indicated that the interfaces may be beneficial to reduce the overall thermal expansion of the composites. The methods to further decrease composite CTEs are also discussed.

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We have observed possible superconductivity using standard resistance vs. temperature techniques in phosphorous ion implanted Highly Oriented Pyrolytic Graphite. The onset appears to be above 100 K and quenching by an applied magnetic field has been observed. The four initial boron implanted samples showed no signs of becoming superconductive whereas all four initial and eight subsequent samples that were implanted with phosphorous showed at least some sign of the existence of small amounts of the possibly superconducting phases. The observed onset temperature is dependent on both the number of electron donors present and the amount of damage done to the graphene sub-layers in the Highly Oriented Pyrolytic Graphite samples. As a result the data appears to suggest that the potential for far higher onset temperatures in un-damaged doped graphite exists.

We have observed evidence of superconductivity at temperatures in the vicinity of 260 K in phosphorus-doped graphite and graphene. This evidence includes transport current, magnetic susceptibility, Hall effect and (pancake) vortex state measurements. All of these measurements indicate a transition which is that of a type II superconductor with no type I phase until below the limits of our measurement capabilities. Vortex states are inferred from periodically repeated steps in the resistance versus temperature characteristics of highly oriented pyrolytic graphite and exfoliated doped multilayer graphene. Magnetic susceptibility measurements have shown results qualitatively similar to those expected (and experimentally observed by others) for ultra-thin (thickness ≪λL) films. The magnetization is negative for field-cooled and zero-field-cooled measurements. The magnetization for field cooled and zero-field-cooled measurements begin to diverge at approximately 260 K. Hall effect measurements show a sign reversal in the Hall voltage as the temperature is reduced from 300 K to 78 K.

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