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24 results on '"Sims, Zachary C."'

7. Anisotropic neutron spin resonance in underdoped superconducting NaFe1-xCoxAs

Author

Zhang, Chenglin, Song, Yu, Regnault, L. P., Su, Yixi, Enderle, M., Kulda, J., Tan, Guotai, Sims, Zachary C., Egami, Takeshi, Si, Qimiao, and Dai, Pengcheng

Subjects
Condensed Matter - Superconductivity
Abstract

We use polarized inelastic neutron scattering (INS) to study spin excitations in superconducting NaFe0.985Co0.015As (C15) with static antiferromagnetic (AF) order along the a-axis of the orthorhombic structure and NaFe0.935Co0.045As (C45) without AF order. In previous unpolarized INS work, spin excitations in C15 were found to have a dispersive sharp resonance near Er1=3.25 meV and a broad dispersionless mode at Er2=6 meV. Our neutron polarization analysis reveals that the dispersive resonance in C15 is highly anisotropic and polarized along the a- and c-axis, while the dispersionless mode is isotropic similar to that of C45. Since the a-axis polarized spin excitations of the anisotropic resonance appear below Tc, our data suggests that the itinerant electrons contributing to the magnetism are also coupled to the superconductivity., Comment: PRB(R), 2014

Published
2014
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9. Uniaxial pressure effect on structural and magnetic phase transitions in NaFeAs and its comparison with as-grown and annealed BaFe$_2$As$_2$

Author

Song, Yu, Carr, Scott V., Lu, Xingye, Zhang, Chenglin, Sims, Zachary C., Luttrell, N. F., Chi, Songxue, Zhao, Yang, Lynn, Jeffrey W., and Dai, Pengcheng

Subjects
Condensed Matter - Superconductivity
Abstract

We use neutron scattering to study the effect of uniaxial pressure on the tetragonal-to-orthorhombic structural ($T_s$) and paramagnetic-to-antiferromagnetic ($T_N$) phase transitions in NaFeAs and compare the outcome with similar measurements on as-grown and annealed BaFe$_2$As$_2$. In previous work on as-grown BaFe$_2$As$_2$, uniaxial pressure necessary to detwin the sample was found to induce a significant increase in zero pressure $T_N$ and $T_s$. However, we find that similar uniaxial pressure used to detwin NaFeAs and annealed BaFe$_2$As$_2$ has a very small effect on their $T_N$ and $T_s$.Since transport measurements on these samples still reveal resistivity anisotropy above $T_N$ and $T_s$, we conclude that such anisotropy cannot be due to uniaxial strain induced $T_N$ and $T_s$ shifts, but must arise from intrinsic electronic anisotropy in these materials.

Published
2013
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15. Application of Ce for scavenging Cu impurities in A356 Al alloys

Author

Sims, Zachary C., primary, Henderson, Hunter B., additional, Thompson, Michael J., additional, Chaudhary, Rakesh P., additional, Hammons, Joshua A., additional, Ilavsky, Jan, additional, Weiss, David, additional, Anderson, Kevin, additional, Ott, Ryan, additional, and Rios, Orlando, additional

Published
2021
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17. Additively Manufactured Single-Use Molds and Reusable Patterns for Large Automotive and Hydroelectric Components

Author

Henderson, Hunter B., primary, Stromme, Eric T., additional, Kesler, Michael S., additional, Sims, Zachary C., additional, Chesser, Phillip, additional, Richardson, Brad, additional, Thompson, Michael J., additional, Love, Lonnie, additional, Peter, William, additional, Morris, Emily, additional, Rios, Orlando, additional, and Weiss, David, additional

Published
2019
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18. Application of Ce for scavenging Cu impurities in A356 Al alloys

Author

Sims, Zachary C., Henderson, Hunter B., Thompson, Michael J., Chaudhary, Rakesh P., Hammons, Joshua A., Ilavsky, Jan, Weiss, David, Anderson, Kevin, Ott, Ryan, and Rios, Orlando

Abstract

AbstractSecondary (recycled) Al is increasingly used in castings due to its lower cost and carbon footprint relative to primary Al. However, the presence of certain impurity elements in secondary Al degrades its properties, often requiring dilution or downgrading. Scavenging impurities with reactive alloying additions can limit impurity impact and broaden the use of secondary Al. This report will detail the initial results of using Ce to microstructurally tie up Cu impurities present in a model secondary Al alloy (A356) with high Cu impurity. The results show that targeted Ce additions to A356 can be used to scavenge Cu impurities by forming complex intermetallics and inhibit intergranular corrosion susceptibility associated with Cu impurities.Supplemental data for this article is available online at

Published
2022
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19. High performance aluminum–cerium alloys for high-temperature applications

Author

Sims, Zachary C., primary, Rios, Orlando R., additional, Weiss, David, additional, Turchi, Patrice E. A., additional, Perron, Aurelien, additional, Lee, Jonathan R. I., additional, Li, Tian T., additional, Hammons, Joshua A., additional, Bagge-Hansen, Michael, additional, Willey, Trevor M., additional, An, Ke, additional, Chen, Yan, additional, King, Alex H., additional, and McCall, Scott K., additional

Published
2017
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20. Anisotropic neutron spin resonance in underdoped superconducting ${\mathrm{NaFe}}_{1-x}{\mathrm{Co}}_{x}\mathrm{As}$

Author

Zhang, Chenglin, Song, Yu, Dai, Pengcheng, Regnault, L.-P., Su, Yixi, Enderle, M., Kulda, J., Tan, Guotai, Sims, Zachary C., Egami, Takeshi, and Si, Qimiao

Subjects
Condensed Matter::Strongly Correlated Electrons, ddc:530
Abstract

We use polarized inelastic neutron scattering (INS) to study spin excitations in superconducting NaFe0.985Co0.015As (C15) with static antiferromagnetic (AF) order along the a axis of the orthorhombic structure and NaFe0.935Co0.045As (C45) without AF order. In previous unpolarized INS work, spin excitations in C15 were found to have a dispersive sharp resonance near Er1=3.25 meV and a broad dispersionless mode at Er2=6 meV. Our neutron polarization analysis reveals that the dispersive resonance in C15 is highly anisotropic and polarized along the a and c axes, while the dispersionless mode is isotropic similar to that of C45. Since the a-axis polarized spin excitations of the anisotropic resonance appear below Tc, our data suggests that the itinerant electrons contributing to the magnetism are also coupled to the superconductivity.

Published
2014

23. Anisotropic neutron spin resonance in underdoped superconducting NaFe1-xCoxAs.

Author

Chenglin Zhang, Yu Song, Regnault, L.-R., Yixi Su, Enderle, M., Kulda, J., Tan, Guotai, Sims, Zachary C., Egami, Takeshi, Qimiao Si, and Pengcheng Dai

Subjects
*IRON-based superconductors, *SPIN excitations, *INELASTIC neutron scattering, *ANISOTROPY, *ANTIFERROMAGNETIC materials, *SUPERCONDUCTIVITY
Abstract

We use polarized inelastic neutron scattering (INS) to study spin excitations in superconducting NaFe0.985Co0.015As (C15) with static antiferromagnetic (AF) order along the a axis of the orthorhombic structure and NaFe0.935Co0.045As (C45) without AF order. In previous unpolarized INS work, spin excitations in C15 were found to have a dispersive sharp resonance near Er1 = 3 .2 5 meV and a broad dispersionless mode at Er2 = 6 meV. Our neutron polarization analysis reveals that the dispersive resonance in C 15 is highly anisotropic and polarized along the a and c axes, while the dispersionless mode is isotropic similar to that of C45. Since the n-axis polarized spin excitations of the anisotropic resonance appear below Tc, our data suggests that the itinerant electrons contributing to the magnetism are also coupled to the superconductivity. [ABSTRACT FROM AUTHOR]

Published
2014
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24. Uniaxial pressure effect on structural and magnetic phase transitions in NaFeAs and its comparison with as-grown and annealed BaFe2As2.

Author

Yu Song, Carr, Scott V., Xingye Lu, Chenglin Zhang, Sims, Zachary C., Luttrell, N. F., Songxue Chi, Yang Zhao, Lynn, Jeffrey W., and Pengcheng Dai

Subjects
*NEUTRON scattering, *MAGNETIC transitions, *ANTIFERROMAGNETISM, *ELECTRICAL resistivity, *MAGNETIC anisotropy
Abstract

We use neutron scattering to study the effect of uniaxial pressure on the tetragonal-to-orthorhombic structural (Ts) and paramagnetic-to-antiferromagnetic (TN) phase transitions in NaFeAs and compare the outcome with similar measurements on as-grown and annealed BaFe2As2. In previous work on as-grown BaFe2As2, uniaxial pressure necessary to detwin the sample was found to induce a significant increase in zero pressure TN and Ts. However, we find that similar uniaxial pressure used to detwin NaFeAs and annealed BaFe2As2 has a very small effect on their TN and Ts. Since transport measurements on these samples still reveal resistivity anisotropy above TN and Ts, we conclude diat such anisotropy can not be due to uniaxial strain-induced TN and Ts shifts, but must arise from intrinsic electronic anisotropy in these materials. [ABSTRACT FROM AUTHOR]

Published
2013
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