Georgiy Akopov

Georgiy Akopov
Rutgers, The State University of New Jersey | Rutgers · Department of Chemistry (Newark)

Doctor of Philosophy

About

27
Publications
2,790
Reads
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609
Citations
Introduction
Research interests: Inorganic and Solid-State Chemistry. Methods and techniques: Solid-state synthesis, arc-melting, powder and single crystal XRD, SEM/EDS, TGA/DSC. Current project: Rational Synthesis of Novel Non-Centrosymmetric Tetrel-Pnictide Intermetallics.
Additional affiliations
October 2018 - June 2020
Ames Laboratory
Position
  • PostDoc Position
Description
  • Novel non-centrosymmetric metal tetrel pnictides for thermoelectric applications.
October 2014 - October 2018
University of California, Los Angeles
Position
  • PhD Student
Description
  • Superhard metal borides for applications as tools and abrasive materials.
September 2012 - May 2014
Rutgers, The State University of New Jersey, Newark, USA
Position
  • Researcher
Description
  • 1) Metal-organic Frameworks for gas storage and catalysis. 2) Crystal structure and hydrogen bonding in salt complexes of oxalic acid and amines.
Education
July 2014 - November 2018
University of California, Los Angeles
Field of study
  • Solid-State Chemistry
October 2012 - June 2014
Rutgers, The State University of New Jersey
Field of study
  • Chemistry

Publications

Publications (27)
Article
Full-text available
Non‐linear optical materials must possess a balanced combination of laser‐induced damage threshold (LDT) and second‐harmonic generation (SHG) and be phase matchable. In our previous work, chiral and polar La3CuGeS7 was identified as promising non‐linear optical material. Herein, we report the optimization of non‐linear optical properties through re...
Article
Full-text available
Non-linear optical (NLO) materials require a balance of high second-harmonic generation (SHG) signal and laser damage threshold (LDT), as well as phase matchable behavior. Herein, we report a new member of the (RE)6(TM)x(Tt)2Q14 family of compounds, La6PdSi2S14, which, unlike all other reported TM analogues crystallizing in hexagonal P63 space grou...
Article
Full-text available
Centrosymmetric skutterudite RhP3 was converted to a nonsymmorphic and chiral compound RhSi0.3P2.7 (space group P212121) by means of partial replacement of Si for P. The structure, determined by a combination of X‐ray crystallography and solid state 31P NMR, exhibits branched polyanionic P/Si chains that are unique among metal phosphides. A driving...
Article
Full-text available
An innovative method of synthesis is reported for the large and diverse (RE)6(TM) x (Tt)2S14 (RE = rare-earth, TM = transition metals, Tt = Si, Ge, and Sn) family of compounds (∼1000 members, ∼325 contain Si), crystallizing in the noncentrosymmetric, chiral, and polar P63 space group. Traditional synthesis of such phases involves the annealing of e...
Article
Full-text available
Complex polymorphic relationships in the LnSiP3 (Ln = La and Ce) family of compounds are reported. An innovative synthetic method was developed to overcome differences in the reactivities of the...
Article
Full-text available
Noncentrosymmetric (NCS) tetrel pnictides have recently generated interest as nonlinear optical (NLO) materials due to their second harmonic generation (SHG) activity and large laser damage threshold (LDT). Herein nonmetal‐rich silicon phosphides RuSi4P4 and IrSi3P3 are synthesized and characterized. Their crystal structures are reinvestigated usin...
Article
Full-text available
Compared to common types of Au(I) coordination, such as linear, trigonal planar, and tetrahedral units observed in extended solids, the square planar coordination is rare. Au(I)relia, shown in the cover image, exhibits the 3‐centered bonding of Au‐Tt‐Au and Au‐Pn‐Au (on her feathers), square planar cis‐[AuTt2Pn2] units (her pendant), and linear …‐A...
Article
Materials with superior hardness can be categorized as ultrahard (Vickers hardness, Hv ≥ 80 GPa) and superhard (Hv ≥ 40 GPa). These materials are commonly used as cutting tools and abrasives in the machining and manufacturing industries. With its extreme hardness, diamond is the best known and most used ultrahard material for industrial application...
Article
Full-text available
Three novel isostructural equiatomic gold tetrel pnictides, AuSiAs, AuGeP, and AuGeAs, were synthesized and characterized. These phases crystallize in the noncentrosymmetric (NCS) monoclinic space group Cc (No. 9), featuring square planar Au within cis -[AuTt 2 Pn 2 ] units ( Tt = tetrel, Si, Ge; Pn = pnictogen, P, As). This is in drastic contrast...
Article
Full-text available
La 2 SiP 4 ( mP ‐28, Z = 4, Wyckoff sequence e 7 , space group P 2 1 / c (No. 14), a = 10.8230(6) Å, b = 7.5208(4) Å, c = 7.9189(4) Å, and β = 105.389(2) o ) which crystallizes in the La 2 CuS 4 structure type is reported. Instead of isolated CuS 3 triangles bridged by disulfide anions, in the crystal structure of La 2 SiP 4 , one‐dimensional zig‐z...
Article
Full-text available
The deformation behavior of the three metal dodecaborides (YB12, ZrB12, and Zr0.5Y0.5B12) is investigated using radial X‐ray diffraction under nonhydrostatic compression up to ≈60 GPa with a goal of understanding how bonding and metal composition control hardness. Zr0.5Y0.5B12, which has the highest Vickers hardness (Hv = 45.8 ± 1.3 GPa at 0.49 N l...
Article
Single-phase metal dodecaboride (MB12) solid solutions, Zr0.5Y0.5B12 and Zr0.5U0.5B12 were prepared by arc melting from the pure elements. The phase purity and composition were established by powder X-ray diffraction (PXRD), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and ¹⁰B and ¹¹B solid-state nuclear magnet...
Article
Solid solutions of tungsten diboride (WB2) with increasing substitution of tungsten (W) by tantalum (Ta) and niobium (Nb) - ranging from 0 to 50 at. % on a metals basis - were synthesized through resistive arc melting. Samples were characterized using a combination of powder X-ray diffraction (PXRD) for phase identification, energy-dispersive X-ray...
Article
Metal borides of the YCrB4, Y2ReB6, Y3ReB7 and YMo3B7 structural types, and their solid-solutions were analyzed using powder X-ray diffraction and energy-dispersive X-ray spectroscopy, and studied for their mechanical properties. These metal borides possess unique crystal structures, not found in any other type of borides: alternating metal and bor...
Article
Full-text available
Previous efforts toward the synthesis of materials with superior mechanical properties (e.g., superhardness, high bulk modulus, and high shear modulus) have focused on binary metal boride structures with short covalent bonds. In this paper, we discuss the methods for enhancing the intrinsic and extrinsic hardening factors commonly used to achieve t...
Article
Tungsten tetraboride (WB4) solid-solutions with Y, Sc, Gd, Tb, Dy, Ho and Er were prepared by arc-melting and investigated for their thermal stability and mechanical properties. The phase composition and purity were confirmed by powder X-ray diffraction (PXRD) and energy dispersive X-ray spectroscopy (EDS). In all cases, except for Sc, a change to...
Article
Samples of metal borides with a nominal composition of ((M1)(1-x-z)(M2)(x)(M3)(z)) : 20B (M1, M2 and M3 = Zr, Y, Hf and Gd) were prepared by arc-melting and studied for phase composition (using powder X-ray diffraction (PXRD) and energy dispersive X-ray spectroscopy (EDS)) and mechanical properties (Vickers hardness). Ternary metal dodecaborides ph...
Article
Tungsten tetraboride is an inexpensive, superhard material easily prepared at ambient pressure. Unfortunately, there are relatively few compounds in existence that crystallize in the same structure as tungsten tetraboride. Furthermore, the lack of data in the tetraboride phase space limits the discovery of any new superhard compounds that also poss...
Article
Polyaniline is known for reversible acidic doping. However, despite extensive work, little experimental evidence exists for the initial doping mechanism mainly due to the difficulty of synthesizing polyaniline with a uniform chain length. In this study, we partially dope aniline tetramers in order to investigate the initial stage of doping in both...
Article
For decades, borides have been primarily studied as crystallographic oddities. With such a wide variety of structures (a quick survey of the Inorganic Crystal Structure Database counts 1253 entries for binary boron compounds!), it is surprising that the applications of borides have been quite limited despite a great deal of fundamental research. If...
Article
We report ambient pressure stabilization of a previously synthesized high-pressure (6.5 GPa) phase, GdB12, in a Zr1-xGdxB12 solid solution (with ∼54 at. % Gd solubility, as determined by both powder X-ray diffraction and energy-dispersive spectroscopy). Limited solubilities of Sm (∼15 at. % Sm), Nd (∼7 at. % Nd), and Pr (∼4 at. % Pr), in ZrB12 were...
Article
The primary focus of superhard materials development has relied on chemical tuning of the crystal structure. While these intrinsic effects are invaluable, there is a strong possibility that hardness can be dramatically enhanced using extrinsic effects. Here, we demonstrate that the superhard metal W0.5 Ta 0.5B can be prepared as nanowires through f...
Article
The solid solutions Zr1-xYxB12, Zr1-xScxB12, and Y1-xScxB12 (x = 0—1) as well as ScB50 and YB66 are prepared by arc-melting of the elements in ratios of 1:20 for the dodecaborides and 1:65 and 1:70 for the latter two binary phases.
Article
Solid solutions of mixed metal dodecaborides of ZrB12, YB12, and ScB12 were prepared by arc-melting and studied for their mechanical properties. Zr1-xYxB12 formed an essentially perfect solid solution, closely following Vegard's law. Zr1-xScxB12 and Y1-xScxB12 undergo a face centered-cubic to body-centered tetragonal transition at 90-95 at. % Sc as...
Article
The high-pressure HfB12 phase is stabilized in the Y1-xHfxB12 (x = 0.00, 0.05, 0.25, 0.50, 0.75, 0.95) system (obtained by arc-melting of the elements) under ambient pressure.
Article
Alloys of tungsten tetraboride (WB4) with the group 4 transition metals, titanium (Ti), zirconium (Zr), and hafnium (Hf), of different concentrations (0–50 at. % on a metals basis) were synthesized by arc-melting in order to study their mechanical properties. The phase composition and purity of the as-synthesized samples were confirmed using powder...
Article
Alloys of metal dodecaborides—YB12 with HfB12—were prepared via arc-melting in order to stabilize the metastable HfB12 high-pressure phase under ambient pressure. Previously, HfB12 had been synthesized only under high-pressure (6.5 GPa). Powder X-ray diffraction (PXRD) and energy-dispersive X-ray spectroscopy (EDS) were used to confirm the purity a...

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Projects

Project (1)
Project
Design of novel metal boride materials with superior mechanical (superhardness) and thermal oxidation properties.