Search NASA⌕ Search

SEARCH · Search NASA

Results for “NICKEL COMPOUNDS”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Two good metals make a semiconductor: A potassium-nickel compound under pressure

We predict a potassium-nickel intermetallic compound K 2 Ni at high pressure and identify it as the long-sought structure of the only known K-Ni compound to date. Although both constituent elements are metallic, K 2 Ni exhibits a semiconducting ground state with an indirect band gap of 0.65 eV. Electron instability due to the degeneracy at the Fermi level arises from the particular motif of the structure, which in turn induces symmetry-breaking Peierls distortion and a nonmetallic ground state. Overall, the results indicate that the chemical properties of elements can change dramatically under extreme conditions and have significant implications for the postulation that potassium is incorporated in Earth's core.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Synthesis of Xenon and Iron-Nickel Intermetallic Compounds at Earth’s Core Thermodynamic Conditions

In this study, using in situ synchrotron x-ray diffraction and Raman spectroscopy in concert with first principles calculations we demonstrate the synthesis of stable Xe(Fe ,Fe/Ni) 3 and XeNi 3 compounds at thermodynamic conditions representative of Earth’s core. Surprisingly, in the case of both the Xe-Fe and Xe-Ni systems Fe and Ni become highly electronegative and can act as oxidants. In conclusion, the results indicate the changing chemical properties of elements under extreme conditions by documenting that electropositive at ambient pressure elements could gain electrons and form anions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Composition for fuel cell electrode

In some examples, a fuel cell comprising an anode; an electrolyte; cathode barrier layer; and a nickelate composite cathode separated from the electrolyte by the cathode barrier layer; and a cathode current collector layer. The nickelate composite cathode includes a nickelate compound and an ionic conductive material, and the nickelate compound comprises at least one of Pr.sub.2NiO.sub.4, Nd.sub.2NiO.sub.4, (Pr.sub.uNd.sub.v).sub.2NiO.sub.4, (Pr.sub.uNd.sub.v).sub.3Ni.sub.2O.sub.7, (Pr.sub.uNd.sub.v).sub.4Ni.sub.3O.sub.10, or (Pr.sub.uNd.sub.vM.sub.w).sub.2NiO.sub.4, where M is an alkaline earth metal doped on an A--site of Pr and Nd. The ionic conductive material comprises a first co-doped ceria with a general formula of (A.sub.xB.sub.y)Ce.sub.1-x-yO.sub.2, where A and B of the first co-doped ceria are rare earth metals. The cathode barrier layer comprises a second co-doped ceria with a general formula (A.sub.xB.sub.y)Ce.sub.1-x-yO.sub.2, where at least one of A or B of the second co-doped ceria is Pr or Nd.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2016

Theoretical investigation of the electronic structure of a substituted nickel phthalocyanine

The optimized geometry and electronic structure of an organic compound nickel phthalocyanine tetrasulfonic acid tetra sodium salt have been investigated using density functional theory. We have also optimized the structure of nickel phthalocyanine tetrasulfonic acid tetra sodium salt in dimethyl sulfoxide to study effects of solvent on the electronic structure and transitions. Experimentally, the electronic transitions have been studied using UV-VIS spectroscopic technique. It is observed that the electronic transitions obtained from the theoretical studies generally agree with the experiment.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2022

Effect of disorder on thermodynamic instability of binary Rare-earth – Nickel – Palladium compounds

In this work, we have investigated the thermodynamic stability of disordered rare-earth phases SmX 2 and Sm 10 X 21 (X=Ni, Pd) using machine-learning based analytical descriptor and first-principles density functional theory methods. The absence of Laves phase compounds in R-Pd binary systems is a longstanding problem of rare earth science: even though Ni and Pd belong to the same group of the periodic table and have similar electronic structure, the Pd compound crystallizes in a monoclinic (C2/m) phase with 10:21 stoichiometry, i.e., Sm 10 Pd 21 , while the Ni compound adopts a cubic Laves phase (MgCu 2 ) structure. To understand this contrasting phase stability, we performed thermodynamic convex hull analysis of Sm x Ni 1-x and Sm x Pd 1-x binary systems, which is experimentally validated using powder X-ray diffraction (PXRD) analyzes of polycrystalline Sm(Ni x Pd 1-x ) 2 samples with x=0, 0.5, and 1. A detailed electronic-structure (band-structure, charge density, and Fermi-surface) analysis of the differences between SmNi 2 /SmPd 2 and Sm 10 Ni 21 /Sm 10 Pd 21 compounds provides the quantum mechanical origin of the unfavorable mixing of Pd with Ni in cubic Laves phase. We show that the stability of Sm-Pd in 10:21 stoichiometry arises from improved intra-/inter-layer 5d-4d bonding compared to the 1:2 stoichiometry. Our work emphasizes the importance of ab-initio methods and computationally inexpensive analytical descriptors for the detailed analysis of thermodynamic and electronic properties of hard-to-prepare rare-earth compounds.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Hydrodeoxygenation of phenolic compounds to cycloalkanes over supported nickel phosphides

SiO2, HZSM-5 and Al2O3 were used to support nickel phosphides to prepare hydrodeoxygenation (HDO) catalysts. The nickel loading was kept at 20 wt% while the Ni/P molar ratio was varied among 3, 2, and 1 in the preparation by incipient wetness impregnation. XRD characterization revealed that Ni3P, Ni12P5, and Ni2P as the major crystal phases were obtained at Ni/P ratio of 3, 2, and 1, respectively, on SiO2 and HZSM-5. When Al2O3 was used as the support, nickel metal rather than nickel phosphides was generated. Among SiO2-supported nickel phosphides, Ni3P exhibited highest hydrogenation activity and catalytic performance in phenol HDO. Ni3P/HZSM-5 showed the high catalytic performance in HDO of phenol as well as catechol and o-cresol, with Ni3P as the hydrogenation site and the acid sites in HZSM-5 zeolite as the dehydration site. The strong acidity in HZSM-5 also facilitated the isomerization of cycloalkanes at elevated temperatures.

Hydrodeoxygenation, phenolic compound, nickel phos↗
NASA NTRS1983

Technique for manufacturing nickel electrodes

A method of manufacturing nickel electrodes distinctive for its use of a composite material for the electrode made up of nickel compound, electrode material, cobalt in metal form or cobalt in compound form is investigated. The composite is over-discharged (same as reverse charging) in an alkaline solution. After dealkalization, synthetic resin adhesive is added and the electrode is formed. Selection of the cobalt compound is made from a group consisting of cobalt oxide, cobalt hydroxide, cobalt carbonate and cobalt sulfate. The method upgrades plate characteristics by using an active material in a non-sintered type nickel electrode, which is activated by electro-chemical effect.

Yamazaki, H.↗
DOE OSTI2019

Enhancement of Magnetization and Tailoring of Blocking Temperatures of Nano-Ni–Zn Ferrite Powder Synthesized Using Microwave-assisted Combustion Method

Single-phase nano-Ni–Zn ferrite samples in the range of 6 to 75 nm were synthesized using microwave-assisted combustion method. Enhancement of saturation magnetization (M{sub s}) was observed in comparison with previously reported results. Minor variation of (M{sub s}) due to composition change can be explained on the basis of strengthening of A–B exchange interaction due to replacement of nonmagnetic Zn ions by Ni ions. Low coercivity (H{sub c}) and retentivity (M{sub r}) indicate low loss in the samples. SQUID analysis showed that the blocking temperature (T{sub B}) of the samples can be tailored in the present work.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

The Ideal Strengths of Superconducting MgCNi{sub 3} and CdCNi{sub 3}

The stress-strain curves under tensile deformation in the 〈100〉, 〈110〉, and 〈111〉 directions and under shear deformation in the (001)〈110〉, (110)〈1̄10〉, (111)〈11̄0〉, and (111)〈112̄〉 slip systems have been systematically calculated by first-principles method to study the ideal strengths of superconducting MgCNi{sub 3} and CdCNi{sub 3}. The ideal strengths in the three tensile directions are found to be reduced in the order of 〈100〉 → 〈110〉 → 〈111〉 and those for the four shear slip systems in the order of (110)〈1̄10〉→(111)〈112̄〉→(111)〈11̄0〉→(001)〈110〉 for both superconductors. Their lowest ideal tensile strengths are found to be larger than the corresponding highest ideal shear strengths, which could explain why both superconductors have the ductility. The obtained lattice constants and elastic properties coincide well with the the available experimental and theoretical values.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Magneto-electronic and Thermodynamic Properties of Quaternary NiFeMnZ (Z = In, Sn) New Spin Gapless Semiconductors

This paper deals with investigation of magneto-electronic and thermodynamic properties of new spin gapless semiconductor quaternary NiFeMnZ (Z = In, Sn) Heusler alloys. In addition, electronic properties such as band structure and density of states were studied in detail. The obtained results are based on first-principles calculations, using the full potential linearized augmented plane wave (FP-LAPW) method within well-known generalized gradient approximation (GGA) coupling with spin-orbit calculation (SOC) in framework of the density functional theory (DFT) implemented in the WIEN2k package. As results, the alloys were found to be new spin gapless semiconductors (SGSs), and both compounds in LiMgPdSn-type crystal structure are stable. The magnetic moment of NiFeMnIn and NiFeMnSn was 4.39 and 4.99 μ{sub B} per formula unit, respectively. This result is in agreement with the Slater-Pauling rule (M{sub tot} = 24 −Z{sub tot}). Furthermore, the thermodynamic properties were also predicted. All these multifunctionalities lead to crucial interest for developing future spintronics device generations.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Realization of Magnetostructural Transition and Magnetocaloric Properties of Ni–Mn–Mo–Sn Heusler Alloys

As magnetic cooling refrigerant, Ni–Mn–Sn Heusler alloys have gained significant potentials for a wide range of practical applications as compared with other expensive Ga-doped Ni–Mn based Heusler alloys, toxic As and P doped Mn-based alloys and rare-earth elements like Gd-based alloys. Consequently, an inclusive investigation on magnetostructural transition and magnetocaloric features of Ni{sub 43}Mn{sub 47−x}Mo{sub x}Sn{sub 10} alloys is carried out. The alloys are assembled through arc-melting technique and their X-ray diffraction analysis confirms their B{sub 2}-type crystal structure at room temperature. As the Mo contents are increased, the magnetostructural transition temperature increases for a temperature range between Curie temperature of austenite and martensite phases. Obvious metamagnetic behavior and magnetic hysteresis are observed in isothermal magnetization curves, suggesting that the temperature and magnetic field can be used as robust tools for tuning the structural transformation in Heusler alloys. The noticeable magnetocaloric effect suggests that the prepared alloys can be an attractive choice for magnetic refrigeration applications.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

The Theoretical Investigation of Electronic, Magnetic, and Thermoelectric Behavior of LiZ{sub 2}O{sub 4} (Z = Mn, Fe, Co, and Ni) by Modified Becke and Johnson Approach

Magnetic spinel oxides LiZ{sub 2}O{sub 4} (Z = Mn, Fe, Co, and Ni) have recently appealed the scientific community due to their interesting magnetic and thermoelectric applications. In the current article, the electronic, magnetic, and thermoelectric properties of LZO have been elaborated using density functional theory-based Wien2k code. The band structures and total density of states ensure the half metallic ferromagnetic (HMF) nature of the studied compounds. Furthermore, the magnetism is discussed in detail using crystal field, John-Teller, and exchange energies involved in the system and spin density. Finally, electrical conductivity, thermal conductivity, power factor, Seebeck coefficient, and thermal efficiency computed by using BoltztraP code suggest these compounds for thermoelectric device fabrications.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Complicated Magnetic Phases and Presence of Exchange Bias in Off-Stoichiometric Mn{sub 50}Ni{sub 25 + x}In{sub 25−x} Heusler Alloys

The martensitic transformation (MT), magnetic phases, and exchange bias (EB) effect in Mn{sub 50}Ni{sub 25 + x}In{sub 25−x} (x = 14.5∼18) Heusler alloys have been investigated. The MT and magnetic state can be tuned significantly by modifying the Ni/In ratio, while the Curie temperature (T{sub C}) remains almost unchanged. With increase of the Ni/In ratio, the ferromagnetic components in the studied samples decrease continuously, while the antiferromagnetic components increase and it therefore enhances the exchange interaction as well. All of the samples exhibit negative horizontally shifted loops after field-cooled procedure. In addition, the samples with the compositional range of 15 ≤ x ≤ 16 also present the EB effect in zero field-cooled condition. To evaluate the causes of this scenario, EB field and coercive field as a function of temperature and cooling field have been investigated. The experimental results imply that the spin reconfiguration of superspin glass (SSG) clusters and the competition between antiferromagnetic and ferromagnetic interactions can account for the behavior of EB effect.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Characteristics of Magnetization Reversal of Magnetostatically Coupled Microwire-Based System

The magnetization reversal process of a system consisted of one Co{sub 67}Fe{sub 3.9}Ni{sub 1.5}B{sub 12.5}Si{sub 14.5}Mo{sub 0.6} and one Fe{sub 74}B{sub 13}Si{sub 11}C{sub 2} microwires was studied. The change of the magnetic characteristics of a system (slope and shape of the hysteresis loop, coercive force) under effect of the neighbor and the length of the system (in the range of 3–20 mm) was considered and analyzed in terms of effective demagnetizing field influence.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Tuning the Ground State and Its Relationship to Zero-Field-Cooled Exchange Bias in NiMnSnAl Alloys

The crystal structure, phase transitions, and exchange bias (EB) in Al-doped Ni{sub 50}Mn{sub 36}Sn{sub 14-x}Al{sub x} Heusler alloys were investigated. With the increase of Al content, the cell volume decreases gradually, and the martensitic transformation temperature shifts to a higher temperature. Due to the positive “chemical pressure” by Al substitution, the antiferromagnetic interaction strengthens, leading to the decrease of magnetization and the ground state evolution from “reentrant” spin glass to spin glass. Zero-field-cooled EB is triggered in samples exhibiting spin-glass ground state. These results suggest a viable way to design Ni-Mn-Z-based alloys showing zero-field-cooled EB by tuning the exchange interactions and ground state via lattice modulation.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Study on Static Recrystallization Behavior of Medium-Carbon Cr-Ni-Mo Alloyed Steel During Hot Deformation

A series of two-pass hot compression tests were conducted on Gleeble-1500 thermo-mechanical simulator to investigate the static recrystallization (SRX) behavior of a medium-carbon Cr-Ni-Mo alloyed steel 34CrNiMo. The compression tests were performed at a deformation temperature range of 950-1150 °C, a strain rate range of 0.1-3.5 s{sup −1}, and an interval time range of 1-100 s. The experimental flow stress curves and microstructural observation indicate that deformation temperature, pass interval time, strain rate, and pre-strain have significant influences on the recrystallization behavior of 34CrNiMo steel. It is identified that the softening fraction increases with the increasing deformation temperature, pre-strain, and interval time, while it decreases with the increasing strain rate. Based on the experimental data, the SRX kinetics equations of 34CrNiMo steel were developed. And the calculated results are in good agreement with the experimental ones, which demonstrates that the established equations can be used to describe the SRX behavior of 34CrNiMo steel at elevated temperatures.

36 MATERIALS SCIENCE↗