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Arthur Mar

Bio: Arthur Mar is an academic researcher from University of Alberta. The author has contributed to research in topics: Crystal structure & Ternary operation. The author has an hindex of 28, co-authored 313 publications receiving 3980 citations. Previous affiliations of Arthur Mar include Lviv University & Auburn University.


Papers
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Journal ArticleDOI
TL;DR: Atomic charges determined from the P 2p core line spectra and the fitted valence-band spectra support the approximate formulation M(1+)P(1-) for these phosphides, reaffirming the notion that these transition-metal phosphides have considerable metallic character.
Abstract: The binary transition-metal monophosphides CrP, MnP, FeP, and CoP have been studied with X-ray photoelectron spectroscopy. The shifts in phosphorus 2p3/2 core line binding energies relative to that...

390 citations

Journal ArticleDOI
TL;DR: A machine learning model has been trained to discover Heusler compounds, which are intermetallics exhibiting diverse physical properties attractive for applications in thermoelectric and spintronic materials as discussed by the authors.
Abstract: A machine-learning model has been trained to discover Heusler compounds, which are intermetallics exhibiting diverse physical properties attractive for applications in thermoelectric and spintronic materials. Improving these properties requires knowledge of crystal structures, which occur in three subtle variations (Heusler, inverse Heusler, and CsCl-type structures) that are difficult, and at times impossible, to distinguish by diffraction techniques. Compared to alternative approaches, this Heusler discovery engine performs exceptionally well, making fast and reliable predictions of the occurrence of Heusler vs non-Heusler compounds for an arbitrary combination of elements with no structural input on over 400 000 candidates. The model has a true positive rate of 0.94 (and false positive rate of 0.01). It is also valuable for data sanitizing, by flagging questionable entries in crystallographic databases. It was applied to screen candidates with the formula AB2C and predict the existence of 12 novel gall...

270 citations

Journal ArticleDOI
TL;DR: In this article, the electronic structures of metal-rich binary phosphides M2P and M3P (M = Cr−Ni) have been examined by means of X-ray photoelectron and absorption spectroscopy and compared with those of the monophosphides MP.
Abstract: The electronic structures of metal-rich binary phosphides M2P and M3P (M = Cr−Ni) have been examined by means of X-ray photoelectron and absorption spectroscopy and compared with those of the monophosphides MP. The P 2p3/2 binding and P K-edge absorption energies decrease with greater ionic character of the M−P bonding and indicate the presence of anionic phosphorus, contrary to previous theoretical assertions but consistent with our previous results. Interatomic effects play a more important role in affecting the energy shifts in these metal-rich phosphides than in the monophosphides, becoming more pronounced with higher metal concentration. Although the M 2p3/2 XPS spectra show no discernible shifts in binding energies, they reveal satellite features whose intensity can be related to metal charge in the Co- and Ni-containing phosphides. In these cases, the metal charge becomes less positive with higher metal concentration. For Ni2P and Ni3P, this trend was confirmed from an analysis of the Ni L-edge and...

220 citations

Journal ArticleDOI
20 Jul 2018-ACS Nano
TL;DR: Design of Experiments (DoE) is ideally suited for multivariable analyses: by planning one's experiments as per the principles of DoE, one can test and optimize several variables simultaneously, thus accelerating the process of discovery and optimization while saving time and precious laboratory resources.
Abstract: Most discoveries in materials science have been made empirically, typically through one-variable-at-a-time (Edisonian) experimentation. The characteristics of materials-based systems are, however, neither simple nor uncorrelated. In a device such as an organic photovoltaic, for example, the level of complexity is high due to the sheer number of components and processing conditions, and thus, changing one variable can have multiple unforeseen effects due to their interconnectivity. Design of Experiments (DoE) is ideally suited for such multivariable analyses: by planning one’s experiments as per the principles of DoE, one can test and optimize several variables simultaneously, thus accelerating the process of discovery and optimization while saving time and precious laboratory resources. When combined with machine learning, the consideration of one’s data in this manner provides a different perspective for optimization and discovery, akin to climbing out of a narrow valley of serial (one-variable-at-a-time...

205 citations

Journal ArticleDOI
TL;DR: A new mercury selenide BaHgSe2 was synthesized, which displays a large nonlinear optical (NLO) response and melts congruently.
Abstract: A new mercury selenide BaHgSe2 was synthesized. This air-stable compound displays a large nonlinear optical (NLO) response and melts congruently. The structure contains chains of corner-sharing [HgSe3]4– anions in the form of trigonal planar units, which may serve as a new kind of basic functional group in IR NLO materials to confer large NLO susceptibilities and physicochemical stability. Such trigonal planar units may inspire a path to finding new classes of IR NLO materials of practical utility that are totally different from traditional chalcopyrite materials.

151 citations


Cited by
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Journal ArticleDOI
TL;DR: Biesinger et al. as mentioned in this paper proposed a more consistent and effective approach to curve fitting based on a combination of standard spectra from quality reference samples, a survey of appropriate literature databases and/or a compilation of literature references and specific literature references where fitting procedures are available.

7,498 citations

Journal ArticleDOI
26 Jul 2018-Nature
TL;DR: A future in which the design, synthesis, characterization and application of molecules and materials is accelerated by artificial intelligence is envisaged.
Abstract: Here we summarize recent progress in machine learning for the chemical sciences. We outline machine-learning techniques that are suitable for addressing research questions in this domain, as well as future directions for the field. We envisage a future in which the design, synthesis, characterization and application of molecules and materials is accelerated by artificial intelligence.

2,295 citations

Journal ArticleDOI
TL;DR: An overview of recent development of TMP nanomaterials as catalysts for hydrogen generation with high activity and stability is presented, and specific strategies to further improve the catalytic efficiency and stability of T MPs by structural engineering are demonstrated.
Abstract: The urgent need of clean and renewable energy drives the exploration of effective strategies to produce molecular hydrogen. With the assistance of highly active non-noble metal electrocatalysts, electrolysis of water is becoming a promising candidate to generate pure hydrogen with low cost and high efficiency. Very recently, transition metal phosphides (TMPs) have been proven to be high performance catalysts with high activity, high stability, and nearly ∼100% Faradic efficiency in not only strong acidic solutions, but also in strong alkaline and neutral media for electrochemical hydrogen evolution. In this tutorial review, an overview of recent development of TMP nanomaterials as catalysts for hydrogen generation with high activity and stability is presented. The effects of phosphorus (P) on HER activity, and their synthetic methods of TMPs are briefly discussed. Then we will demonstrate the specific strategies to further improve the catalytic efficiency and stability of TMPs by structural engineering. Making use of TMPs as cocatalysts and catalysts in photochemical and photoelectrochemical water splitting is also discussed. Finally, some key challenges and issues which should not be ignored during the rapid development of TMPs are pointed out. These strategies and challenges of TMPs are instructive for designing other high-performance non-noble metal catalysts.

2,104 citations

Journal ArticleDOI
TL;DR: The topotactic fabrication of self-supported nanoporous cobalt phosphide nanowire arrays on carbon cloth via low-temperature phosphidation of the corresponding Co(OH)F/CC precursor offers excellent catalytic performance and durability under neutral and basic conditions.
Abstract: In this Communication, we report the topotactic fabrication of self-supported nanoporous cobalt phosphide nanowire arrays on carbon cloth (CoP/CC) via low-temperature phosphidation of the corresponding Co(OH)F/CC precursor. The CoP/CC, as a robust integrated 3D hydrogen-evolving cathode, shows a low onset overpotential of 38 mV and a small Tafel slope of 51 mV dec–1, and it maintains its catalytic activity for at least 80 000 s in acidic media. It needs overpotentials (η) of 67, 100, and 204 mV to attain current densities of 10, 20, and 100 mA cm–2, respectively. Additionally, this electrode offers excellent catalytic performance and durability under neutral and basic conditions.

2,063 citations

Journal ArticleDOI
TL;DR: In this paper, a scheme for fitting the Ni 2p spectra using multiplet envelopes is proposed, based on charge transfer assignments of the main peak at 854.6 eV and the broad satellite centred at around 861 eV to the cd 9 L and the unscreened cd 8 final state configurations, respectively.

1,589 citations