Hafnium oxide non-volatile memories have shown promise as an artificial synapse in neuromorphic computing architectures. However, there is still a need to fundamentally understand how reliably control the analog resistance change induced by oxygen ions that partially rupture or re-form conductive filament. In this work, impact of measurement conditions (pulse amplitude and pulse width) titanium...

The recent experimental observation of collective rotational bands up to I > 60h̄ in 175Hf presents theoretical challenges. It is shown here that total Routhian surface calculations are able to explain the yrast high-spin behavior, with collective oblate states favored at I ∼ 35h̄ and strongly deformed prolate states at the highest spins. The collective oblate rotation terminates in noncollective...

Estimates for the martian core formation timescale based on the hafnium–tungsten (Hf–W) isotopic system have varied by almost an order of magnitude, because of uncertainties in the martian mantle Hf/W ratio. Here we argue that the Hf/W ratio is ∼4 but is uncertain by ∼25%, resulting in (instantaneous) martian core formation timescales ranging from 0 to 10 Myr; accordingly, Hf–W isotope observat...

Nanoporous and nonporous three-dimensional silicon nanowire arrays (SiNWAs) prepared with metal-assisted chemical etching method were investigated as photocatalysts in dye photodegradation systematically. In comparison with nonporous SiNWAs, nanoporous SiNWAs have higher surface area, larger pore volume, stronger light absorption and better photocatalytic activity. After the HF-treatment, the p...

The thermal expansion coefficient of Al3Sc and Al3(Sc0:75X0:25), where X is Ti, Y, Zr or Hf, was measured by dilatometry between 25 and 1000 C. The measured value, ð16 1Þ 10 6 K , is constant between 25 and 900 C and insensitive to alloying element. Good agreement is found with a literature value determined from first-principle cal-

Three distinctly different mechanisms are shown to populate the K(pi)=6(+) (t(1/2)=77 ns), 16(+) (31 yr), and 8(-) (4 s) isomer bands of 178Hf by Coulomb excitation. High spin states of the three isomer bands were populated by Coulomb excitation of a hafnium target with a 650 MeV 136Xe beam. Although direct population of high-K bands is highly K-forbidden, isomer bands in 178Hf were populated u...

Scaling of silicon dioxide dielectrics has once been viewed as an effective approach to enhance transistor performance in complementary metal-oxide semiconductor (C-MOS) technologies as predicted by Moore’s law [1]. Thus, in the past few decades, reduction in the thickness of silicon dioxide gate dielectrics has enabled increased numbers of transistors per chip with enhanced circuit functionali...

Hafnium and zirconium are commonly thought to be very similar in chemistry. However, they are surprisingly dissimilar in the chemistry of metal-rich chalcogenides. For instance, Hf2S [1] and Hf2Se [2] are comprised of hexagonal closepacked double metal atom layers spaced by sulfur or selenium while both Zr2S [3] and Zr2Se [4] crystallize in a Ta2P-type structure [5]. Zr2Te [6] and Hf2Te [7] ado...