[ { "id": "authors:a28dg-6n054", "collection": "authors", "collection_id": "a28dg-6n054", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230526-663072000.35", "type": "book_section", "title": "VISTA: Venus in Situ Transfer and Analysis Mission Concept", "book_title": "2023 IEEE Aerospace Conference", "author": [ { "family_name": "Izenberg", "given_name": "Noam", "orcid": "0000-0003-1629-6478", "clpid": "Izenberg-Noam" }, { "family_name": "Scott", "given_name": "Valerie", "orcid": "0000-0002-0267-9833", "clpid": "Scott-Valerie" }, { "family_name": "Fultz", "given_name": "Brent", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "abstract": "After Magellan 30 years ago, US Venus exploration has relied on archived data, Earth-based and flyby observations of missions bound elsewhere, and international efforts such as Venus Express (ESA) and Akatsuki (JAXA) until the selection of NASA Discovery missions VERITAS and DAVINCI and participation in ESA's EnVision. These missions will address a significant number of major science questions about the past and present of Venus. Nevertheless, many additional and crucial questions about the history of Venus, including its similarities and differences from Earth, will remain unresolved even after the success of these new missions. Significant divergences in planetary evolution of Venus and Earth require knowledge that is not obtainable by the selected suite of upcoming missions, but can be attained by an innovative approach in the next 20 years if precursor science and technology paves the way. \n\nIn the same way that the Mars Exploration Rovers, Mars Science Lab, and Perseverance have provided measurements that unravel the mysteries of Mars, the Venus In Situ Transfer and Analysis mission concept (VISTA) provides an opportunity to obtain measurements that cannot be obtained by a simple, short-term mission to Venus. VISTA would provide detailed knowledge of the surface and atmosphere to better understand the origin and evolution of Venus, its geology and former habitability, and the interaction of its surface with the atmosphere. Since the surface environment of Venus is not conducive to long-term missions, we propose a long duration, sky-borne laboratory in the Venus upper atmosphere, maintained at temperatures and pressures favorable for extended laboratory measurements that shed light on the composition and history of minerals and rocks retrieved from the surface. \n\nVISTA is a concept for a flagship mission to collect samples from multiple locations on the planet surface, and from the Venus atmosphere, and deliver them to a highly-capable, long-lived aerial laboratory for detailed analysis with modern instrumentation. Characterizing the composition, structure, and isotopic ratios of these samples will answer questions of surface composition across multiple geologic provinces. These measurements will help answer questions about the\nfundamental branch points in the evolution of Venus. Studies of atmospheric aerosols will support models of cloud formation. The longevity of VISTA will provide further information on\natmospheric circulation, and provide a platform for detecting rare seismic and volcanic events.\n\nAny in situ Venus mission faces significant technical and operational challenges. VISTA shares some challenges with past and current in situ concepts, and presents its own unique challenges (e.g. asset rendezvous, sample processing, and long-lived laboratory platform). This paper describes the architecture and trades of the VISTA mission concept for the aerial laboratory, (multiple) sampling landers, ascent vehicles, and sample retrievers.", "doi": "10.1109/aero55745.2023.10115688", "isbn": "978-1-6654-9033-7", "publisher": "IEEE", "place_of_publication": "Piscataway, NJ", "publication_date": "2023-03", "pages": "1-17" }, { "id": "authors:jzfg6-ejy65", "collection": "authors", "collection_id": "jzfg6-ejy65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160401-084646138", "type": "book_section", "title": "Miscibility gap and phonon thermodynamics of Fe-Au alloys studied by inelastic neutron scattering and nuclear-resonant inelastic x-ray scattering", "book_title": "Radiation Physics: XI International Symposium on Radiation Physics", "author": [ { "family_name": "Mu\u00f1oz", "given_name": "Jorge A.", "clpid": "Mu\u00f1oz-J-A" }, { "family_name": "Fultz", "given_name": "Brent", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Espinosa", "given_name": "G.", "clpid": "Espinosa-G" }, { "family_name": "L\u00f3pez", "given_name": "C. V.", "clpid": "L\u00f3pez-C-V" }, { "family_name": "L\u00f3pez", "given_name": "J. A.", "clpid": "L\u00f3pez-J-A" } ], "abstract": "Recent measurements of the phonon spectra of several Au-rich alloys of face-centered-cubic Fe-Au using inelastic neutron scattering and nuclear-resonant inelastic x-ray scattering are summarized. The Wills-Harrison model, accounting for charge transfer upon alloying, is used to explain the observed negative excess vibrational entropy of mixing, which increases the miscibility gap temperature in the system by an estimated maximum of 550 K and we adjudicate to a charge transfer from the Fe to the Au atoms that results in an increase in the electron density in the free-electron-like states and in stronger sd-hybridization. When Au is the solvent, this softens the Fe\u2013Fe bonds but stiffens the Au\u2013Au and Au\u2013Fe bonds which results in a net stiffening relative to the elemental components.", "doi": "10.1063/1.4927178", "isbn": "978-0-7354-1318-4", "publisher": "American Institute of Physics", "place_of_publication": "Melville, NY", "publication_date": "2015-07-23", "pages": "Art. No. 020001" }, { "id": "authors:3z4nn-enz30", "collection": "authors", "collection_id": "3z4nn-enz30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110210-144233136", "type": "book_section", "title": "M\u00f6ssbauer Spectrometry", "book_title": "Characterization of Materials", "author": [ { "family_name": "Fultz", "given_name": "Brent", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Kaufmann", "given_name": "Elton N.", "clpid": "Kaufmann-E-N" } ], "abstract": "M\u00f6ssbauer spectrometry gives electronic, magnetic, and structural information from within\nmaterials. A M\u00f6ssbauer spectrum is an intensity of \u03b3-ray absorption versus energy for a\nspecific resonant nucleus such as ^(57)Fe or ^(119)Sn. For one nucleus to emit a \u03b3-ray and a second\nnucleus to absorb it with efficiency, both nuclei must be embedded in solids, a phenomenon\nknown as the \"M\u00f6ssbauer effect.\" M\u00f6ssbauer spectrometry looks at materials from the\n\"inside out,\" where \"inside\" refers to the resonant nucleus.\nM\u00f6ssbauer spectra give quantitative information on \"hyperfine interactions,\" which are small\nenergies from the interaction between the nucleus and its neighboring electrons. The three\nhyperfine interactions originate from the electron density at the nucleus (the isomer shift),\nthe gradient of the electric field (the nuclear quadrupole splitting), and the unpaired electron\ndensity at the nucleus (the hyperfine magnetic field). Over the years, methods have been\nrefined for using these three hyperfine interactions to determine valence and spin at the\nresonant atom. Even when the hyperfine interactions are not easily interpreted, they can\noften be used reliably as \"fingerprints\" to identify the different local chemical environments\nof the resonant atom, usually with a good estimate of their fractional abundances. M\u00f6ssbauer\nspectrometry is useful for quantitative phase analyses or determinations of the concentrations\nof resonant element in different phases, even when the phases are nanostructured or\namorphous.\nMost M\u00f6ssbauer spectra are acquired with simple laboratory equipment and a radioisotope\nsource, but the recent development of synchrotron instrumentation now allow for measurements\non small 10 \u00b5m samples, which may be exposed to extreme environments of pressure\nand temperature. Other capabilities include measurements of the vibrational spectra of the\nresonant atoms, and coherent scattering and diffraction of nuclear radiation.\nThis article is not a review of the field, but an instructional reference that explains principles\nand practices, and gives the working materials scientist a basis for evaluating whether or not\nM\u00f6ssbauer spectrometry may be useful for a research problem. A few representative\nmaterials studies are presented.", "doi": "10.1002/0471266965.com069.pub2", "isbn": "978-1-1181-1074-4", "publisher": "John Wiley & Sons", "place_of_publication": "Hoboken, NJ", "publication_date": "2012", "pages": "1259-1280" }, { "id": "authors:8yfk7-wk567", "collection": "authors", "collection_id": "8yfk7-wk567", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200212-155417703", "type": "book_section", "title": "Vibrational Entropy and Local Structures of Solids", "book_title": "Local Structure from Diffraction", "author": [ { "family_name": "Fultz", "given_name": "Brent", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Billinge", "given_name": "S. J. L.", "clpid": "Billinge-S-J-L" }, { "family_name": "Thorpe", "given_name": "M. F.", "clpid": "Thorpe-M-F" } ], "abstract": "There is now widespread evidence that vibrational entropy must be included in an understanding of solid state phase transitions. While the basic principles are known, the individual phenomena that contribute to differences in vibrational entropy of solid phases require much more investigation. \n\nWe do not expect all of the vibrational modes in a solid to have the same dependence on local atomic structure. In ordered and disordered transition metal aluminides, for example, there is a change in the high energy optical modes upon ordering that can account for most of the difference in vibrational entropy. From other studies performed so far, it seems that vibrational entropy is sensitive to the packing of atoms of different size. \n\nAlthough much of the vibrational entropy depends on harmonic effects that can be calculated readily with the phonon DOS, anharmonic effects also make important contributions to the entropies of solid phases. Phonon DOS measurements at different temperatures will provide information about these anharmonic contributions, which have been shown to be important for the hP24 phase of Co\u2083V. \n\nThe hope is that there will emerge, at least for specific classes of materials, systematic trends showing how differences in vibrational entropy depend on the local atomic structure in a material.", "doi": "10.1007/0-306-47077-2_15", "isbn": "978-0-306-45827-9", "publisher": "Springer", "place_of_publication": "Boston", "publication_date": "2002", "pages": "273-294" }, { "id": "authors:5wwcj-a4m37", "collection": "authors", "collection_id": "5wwcj-a4m37", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200224-090409960", "type": "book_section", "title": "A M\u00f6ssbauer Effect Powder Diffractometer", "book_title": "Industrial Applications of the M\u00f6ssbauer Effect", "author": [ { "family_name": "Kriplani", "given_name": "U.", "clpid": "Kriplani-U" }, { "family_name": "Regehr", "given_name": "M. W.", "clpid": "Regehr-M-W" }, { "family_name": "Fultz", "given_name": "B.", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "abstract": "An automated, high-sensitivity M\u00f6ssbauer powder diffractometer is described, and its performance demonstrated with a bcc \u2075\u2077Fe foil sample. Useful diffraction patterns are acquired in about 10 hours. The incoherent and coherent parts of the scattering are readily identified. Both are affected by thickness distortion, but the incoherent part is affected more strongly.", "doi": "10.1007/978-94-010-0299-8_73", "isbn": "978-94-010-3950-5", "publisher": "Springer", "place_of_publication": "Dordrecht", "publication_date": "2002", "pages": "667-672" }, { "id": "authors:c6xnv-y5955", "collection": "authors", "collection_id": "c6xnv-y5955", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200221-100449979", "type": "book_section", "title": "Electronic Structure of Oxygen in Delitiated LiTMO\u2082 Studied by Electron Energy-Loss Spectrometry", "book_title": "New Trends in Intercalation Compounds for Energy Storage", "author": [ { "family_name": "Graetz", "given_name": "J.", "clpid": "Graetz-J" }, { "family_name": "Yazami", "given_name": "R.", "orcid": "0000-0002-0085-5012", "clpid": "Yazami-R" }, { "family_name": "Ahn", "given_name": "C. C.", "clpid": "Ahn-C-C" }, { "family_name": "Rez", "given_name": "P.", "clpid": "Rez-P" }, { "family_name": "Fultz", "given_name": "B.", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Julien", "given_name": "C.", "clpid": "Julien-C" }, { "family_name": "Pereira-Ramos", "given_name": "J. P.", "clpid": "Pereira-Ramos-J-P" }, { "family_name": "Momchilov", "given_name": "A.", "clpid": "Momchilov-A" } ], "abstract": "Lithium transition-metal oxides (LiTMO\u2082) are currently the preferred cathode materials for secondary Li ion batteries. Several of these materials have a layered structure suitable for intercalation compounds owing to their good kinetics and ability to withstand internal strains of Li intercalation. Despite extensive research on this system, it is still not understood how the electronic charge is redistributed during lithiation. Traditionally it has been accepted that the charge on the intercalated Li is accommodated by the transition metal, allowing the O valence to remain 2-. However, recent computational studies suggest that there is substantial charge transfer from the ionic Li to the anion [1,2]. Empirical data from x-ray photoemission spectroscopy (XPS) and x-ray-absorption spectroscopy (XAS) show that LiTMO\u2082 is strongly covalent with available O 2p holes lying in the TM 3d band [3]. These techniques also show a decrease in O 2p holes during Li intercalation indicating an increase in electron density around the O ion [3,4].", "doi": "10.1007/978-94-010-0389-6_32", "isbn": "978-1-4020-0595-4", "publisher": "Springer", "place_of_publication": "Dordrecht", "publication_date": "2002", "pages": "469-474" }, { "id": "authors:n2nzd-atn79", "collection": "authors", "collection_id": "n2nzd-atn79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191009-094001287", "type": "book_section", "title": "Magnetostriction of Polycrystalline Tb-Dy Alloys at Cryogenic Temperatures", "book_title": "Advances in Cryogenic Engineering Materials", "author": [ { "family_name": "Dooley", "given_name": "J.", "clpid": "Dooley-J" }, { "family_name": "Good", "given_name": "N.", "clpid": "Good-N" }, { "family_name": "Graetz", "given_name": "J.", "clpid": "Graetz-J" }, { "family_name": "Chave", "given_name": "R.", "clpid": "Chave-R" }, { "family_name": "Fultz", "given_name": "B.", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Balachandran", "given_name": "U. Balu", "clpid": "Balachandran-U-B" }, { "family_name": "Hartwig", "given_name": "K. Ted", "clpid": "Hartwig-K-T" }, { "family_name": "Gubser", "given_name": "Donald U.", "clpid": "Gubser-D-U" }, { "family_name": "Bardos", "given_name": "Victoria A.", "clpid": "Bardos-V-A" } ], "abstract": "Single crystals of Tb-Dy alloys exhibit magnetostrictive strains and forces sufficiently large to make them useful as actuators in cryogenic mechanical devices. These actuators offer many advantages over piezoelectric actuators and actuators using motion feedthroughs from higher temperature. We are developing textured polycrystalline materials as alternatives to single crystals, since polycrystals are much simpler to prepare and are less costly. Magnetostrictive strains of 56% of the single crystal value are reported for deformation-processed Tb-Dy. We show that substantial magnetostriction can be attained using low cost commercial grade (total purity 99.7%) Tb-Dy material (as opposed to expensive high purity (99.94%) material required for the growth of single crystals). The effect of grain size and texture on magnetostrictive performance is discussed.", "doi": "10.1007/978-1-4615-4293-3_49", "isbn": "978-1-4613-6926-4", "publisher": "Springer", "place_of_publication": "Boston, MA", "publication_date": "2000", "pages": "383-389" }, { "id": "authors:ty7qp-n5158", "collection": "authors", "collection_id": "ty7qp-n5158", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201005-153617648", "type": "book_section", "title": "Kinetics of Disorder \u2192Order Transformations: Thermodynamic Theory Versus Kinetic Rate Theory", "book_title": "Statics and Dynamics of Alloy Phase Transformations", "author": [ { "family_name": "Fultz", "given_name": "Brent", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Turchi", "given_name": "Patrice E. A.", "clpid": "Turchi-P-E-A" }, { "family_name": "Gonis", "given_name": "Anyonios", "clpid": "Gonis-A" } ], "abstract": "In alloys near thermodynamic equilibrium, the state variables change slowly enough so that the alloy is able to sample all microstates available to it. The entropy is well-defined. It is not surprising, although not strictly necessary, for the kinetics to follow the steepest gradient of the free energy function. Far from thermodynamic equilibrium, however, we expect the free energy function to be less useful. An internal energy can be defined, of course, and an entropy can be defined, for example, by counting the microstates accessible to a corresponding system having the same state variables, but in equilibrium at a different temperature. During the kinetic evolution of the alloy, however, not all of these microstates are encountered with equal probability. No physical mechanism of atom movement allows for direct transitions between arbitrary pairs of microstates. If many elementary kinetic events are required for the system to pass from one specific state to another, the internal energy may have already begun to relax before the microstates of the second state are adequately sampled.", "doi": "10.1007/978-1-4615-2476-2_48", "isbn": "9781461360551", "publisher": "Springer", "place_of_publication": "Boston, MA", "publication_date": "1994", "pages": "669-672" }, { "id": "authors:esmqy-cey10", "collection": "authors", "collection_id": "esmqy-cey10", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201005-153617551", "type": "book_section", "title": "Chemical Systematics of Iron-57 Hyperfine Magnetic Field Distributions in Iron Alloys", "book_title": "M\u00f6ssbauer Spectroscopy Applied to Magnetism and Materials Science", "author": [ { "family_name": "Fultz", "given_name": "Brent", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Long", "given_name": "Gary J.", "clpid": "Long-G-J" }, { "family_name": "Grandjean", "given_name": "Fernande", "clpid": "Grandjean-F" } ], "abstract": "There have been several excellent reviews of applications of iron-57 M\u00f6ssbauer spectrometry in physical metallurgy and metals physics. These reviews typically demonstrate applications of the four measurable quantities in M\u00f6ssbauer spectroscopy: recoil-free fraction, isomer shift, quadrupole effect, and hyperfine magnetic field (HMF). The present chapter has a more focused goal. It shows how local, short-range chemical information can be obtained from the HMF distribution of iron-57 nuclei in ferromagnetic bcc alloys.", "doi": "10.1007/978-1-4899-2409-4_1", "isbn": "9781489924117", "publisher": "Springer US", "place_of_publication": "Boston, MA", "publication_date": "1993", "pages": "1-31" }, { "id": "authors:1am8x-r2b62", "collection": "authors", "collection_id": "1am8x-r2b62", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20201005-153617468", "type": "book_section", "title": "Kinetic States of Order in Highly Nonequilibrium Materials", "book_title": "Ordering and Disordering in Alloys", "author": [ { "family_name": "Fultz", "given_name": "Brent", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" } ], "contributor": [ { "family_name": "Yavari", "given_name": "A. R.", "clpid": "Yavari-A-R" } ], "abstract": "Two concepts from the kinetic theory of disorder\u2192order transformations are presented. Kinetics provides control over the path taken en route to equilibrium, permitting different types of microstructures to be synthesized. Variations in microstructural evolution can be parameterized by two or more order parameters. \"Kinetic paths\" through two or more order parameters are convenient for experimental study because they are independent of the vacancy concentration in the material. Saddle points in the free energy surface have little consequence to the thermodynamic state, but if an alloy approaches a saddle point its kinetic evolution tends to stall. This stalled state is an example of a \"pseudostable\" state.", "doi": "10.1007/978-94-011-2886-5_4", "isbn": "9781851667628", "publisher": "Springer Netherlands", "place_of_publication": "Dordrecht", "publication_date": "1992", "pages": "31-42" }, { "id": "authors:kmhpt-44b51", "collection": "authors", "collection_id": "kmhpt-44b51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150211-120450224", "type": "book_section", "title": "Formation of Buried Oxide in MeV Oxygen Implanted Silicon", "book_title": "Silicon-on-Insulator and Buried Metals in Semiconductors", "author": [ { "family_name": "Nieh", "given_name": "C. W.", "clpid": "Nieh-C-W" }, { "family_name": "Xiong", "given_name": "F.", "clpid": "Xiong-F" }, { "family_name": "Ahn", "given_name": "C. C.", "clpid": "Ahn-C-C" }, { "family_name": "Zhou", "given_name": "Z.", "clpid": "Zhou-Z" }, { "family_name": "Jamieson", "given_name": "D. N.", "clpid": "Jamieson-D-N" }, { "family_name": "Vreeland", "given_name": "T., Jr.", "clpid": "Vreeland-T-Jr" }, { "family_name": "Fultz", "given_name": "B.", "orcid": "0000-0002-6364-8782", "clpid": "Fultz-B" }, { "family_name": "Tombrello", "given_name": "T. A.", "clpid": "Tombrello-T-A" } ], "contributor": [ { "family_name": "Sturm", "given_name": "James C.", "clpid": "Sturm-J-C" } ], "abstract": "We have studied the formation of buried oxide in MeV oxygen implanted Si. A continuous oxide layer is formed in the samples implanted with 2x10^(18)/cm^2 oxygen and annealed at 1300\u00b0 C. The microstructures are studied by cross-sectional transmission electron microscopy and high resolution electron microscopy. Chemical information was obtained by electron energy loss spectroscopy. The effects of implantation temperature are studied. Implantation at a low substrate temperature leads to a well-defined buried SiO_2 layer, inhibits the formation of oxide precipitates in the silicon, and reduces silicon inclusions in the SiO_2.", "doi": "10.1557/PROC-107-73", "isbn": "9780931837753", "publisher": "Materials Research Society", "place_of_publication": "Pittsburgh, PA", "publication_date": "1988", "pages": "73-78" } ]