Advances and Discoveries in Non-equilibrium Driven Nanomaterials and Thin Films: On-Demand Oral Presentations
Sponsored by: TMS Functional Materials Division, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Thin Films and Interfaces Committee
Program Organizers: Ritesh Sachan, Oklahoma State University; Amit Pandey, Lockheed Martin Space; Saurabh Puri, Microstructure Engineering; Amber Srivastava, Indian Institute of Technology; Nuggehalli Ravindra, New Jersey Institute of Technology

Monday 8:00 AM
March 14, 2022
Room: Nanostructured Materials
Location: On-Demand Room


Extraordinary Properties of Q-carbon and Diamond Related Materials: Jagdish Narayan1; 1North Carolina State University
    This talk summarizes the formation Q-carbon and Q-BN (new allotrope of carbon and BN) by nonequilibrium laser annealing, and electron and ion irradiations. The Q-phases provide an ideal platform to grow diamond and c-BN epitaxial thin heterostructures and coatings needed for next-generation solid state devices. The Q-phases are the harder than diamond as much as 60%. The Q-carbon is ferromagnetic in pure-form, and shows record high-temperature superconductivity upon doping with boron. The record hardness and superconductivity are interrelated through Debye frequency and electron-phonon interactions. Recently, we have discovered that Q-carbon is extremely resistant to radiation damage, involving atomic displacements. After ion irradiations (5 MeV Au ions), detailed studies show that atomic structure (HRTEM, HAADF) and bonding characteristics (EELS and Raman) of Q-carbon have remained essentially unchanged after 15dpa of radiation damage, which is equivalent to over twenty years of neutron damage in a conventional reactor.

Low-dimensional Titanium Oxynitride Thin Films and Nanowires for Water-splitting and Ultra-high Capacitance Supercapacitors Applications: Dhananjay Kumar1; 1North Carolina A&T State University
    The present research is aimed at the development of low-dimensional titanium oxynitrides, TiNxOy (TiNO), thin films and nanowires for electrochemical supercapacitor and solar water-splitting applications. The advantages of TiNO over other transition metal oxides are associated with the less electronegative and more polarizable characteristics of nitrogen relative to that of oxygen. The synthesis of high-quality multifunctional 2-dimensional (2D) TiNO thin films and 1-dimensional (1D) TiNO nanowires has been accomplished using a binder-free non-clean room-specific pulsed laser deposition method. The electrochemical supercapacitor measurements on the TiNO system using cyclic voltammetry have shown that the specific capacitance values for the TiNO nanowire samples (2,725 mF.cm-2) are nearly six times more than that of the TiNO thin film samples (400 mF.cm-2). The supercapacitor values amongst the highest values reported for the recently top-tier nanoscale electrode materials.

Magnetic Properties of Qausi-2D van der Waals Crystals by Protons and Photons: Srinivasa Rao Singamaneni1; 1University of Texas at El Paso
    van der Waals engineering of magnetism is a topic of increasing research interest in the community at present. I will discuss our recent efforts in manipulating the magnetic properties of quasi-two-dimensional layered Mn3Si2Te6 upon proton irradiation as a function of fluence 1×1015, 5×1015, 1×1016, and 1×1018 H+/cm2. In the second part, I will discuss on the electron spin resonance (ESR) properties of CrCl3 and CrI3 upon photo-excitation. In the case of CrCl3, at 10 K, the ESR signal is shifted from g = 1.492 (dark) to 1.661 (light), line width increased from 376 to 506 Oe, and the signal intensity is reduced by 1.5 times. The observed change in intensity is reversible when the light is cycled on/off. Upon photo-excitation of CrI3, the ESR signal intensity is reduced by 1.9 times; the g-value increased from 1.956 to 1.990; the linewidth increased from 1170 to 1260 Oe at 60 K.

Recent Advances for Highly Stable Practical Potassium Ion Batteries: Qian Liu1; Qingfeng Zhang1; Chengxin Wang2; Rao Apparao3; Bingan Lu1; 1Hunan University; 2Sun Yat-sen University; 3Clemson University
    Potassium ion batteries (PIBs) suffer from limited cycle life and severe decomposition in organic electrolytes. A simple and viable method was developed by which an ultra-thin, uniform, dense and stable artificial inorganic solid-electrolyte interphase (SEI) film can be formed on commercial graphite anodes in traditional carbonate electrolytes. The SEI film endows PIBs with long-cycle stability and high initial Coulombic efficiency (ICE). Next, leveraging sulfur’s pivotal role as a growth promoter, we developed a low-cost large-scale sulfur-assisted synthesis method for graphene. Specifically, a sulfur-assisted method that converts benzene rings of tetraphenyltin into high purity crystalline graphene will be discussed. Our method yields three dimensional few layered graphene microspheres (FLGMs) which exhibit excellent electron mobility and low inter-sheet junction contact resistance that proved ideal for energy storage applications.2 Together, with the SEI-engineered commercial graphite and FLMGs which do not require substrates for their growth, pave the way for PIB-based energy storage devices.

Magneto-optical Properties of Equilibrium and Non-equilibrium Bi-metallic Materials: Philip Rack1; David Garfinkel1; Reece Emery1; Nan Tang1; Dustin Gilbert1; 1University Of Tennessee
    Bimetallic materials with magnetic and plasmonic responses are candidates for enhanced bioimaging and therapeutics. We will overview our recent work exploring magneto-plasmonic materials in the AgxNi1-x, AuxNi1-x, AuxCo1-x systems. Combinatorial co-sputtering is used to deposit thin films and the composition and microstructure are correlated to the substrate position. Fast quenching from the vapor phase results in supersaturated solid solutions of the otherwise low miscibility equilibrium materials. Pulsed laser induced dewetting is used to rapidly melt sub 20 nm thick films, which induces dewetting of the film and generates functional nanoparticles. The optical and magnetic properties of the alloys in various equilibrium and non-equilibrium states will be overviewed. We will also overview an in situ laser delivery system equipped onto our scanning transmission electron microscope, and show photothermal in situ phase separation as well as excited state electron energy loss spectroscopy to reveal the plasmonic nearfield properties of the materials.

Salt-assisted Chemical Vapor Deposition Synthesis of 2D WSe2 and Its Integration in High Performance Field-effect Transistors: Anupama Kaul1; Avra Bandyopadhyay1; 1University of North Texas
    Two-dimensional (2D) layered materials range in composition from mono-elemental systems such as graphene and black phosphorus, binary transition-metal dichalcogenides (TMDCs) such as WSe2, as well as multi-component organo-halide perovskites. Despite the varying compositions, their unifying feature arises from the weak van der Waals (vdW) interaction that serves as the glue between adjacent layers. The excitonic and multibody interactions in some semiconducting 2D vdW crystallites, their strain-dependent properties and pristine atomically flat interfaces, coupled with the ability to solution-process these materials, offer a rich playground to unveil fundamental physical mechanisms for exciting and innovative devices. I will discuss our efforts in the halide-assisted- (HA-) low-pressure- (LP-) chemical vapor deposition (CVD) synthesis of monolayer (1L) WSe2 on SiO2/Si and sapphire substrates, respectively. The temperature-dependent photoluminescence spectra from 1L WSe2 validated the presence of exciton and trion emission peaks, with the former evident even at room T due to their large binding energies.

Exploring Functional Nanomaterials at XTIP Beamline: Nozomi Shirato1; 1Argonne National Laboratory
    Advancement of functional thin films have shown superior performance and enhanced properties compared to traditional bulk systems. Sametime, a characterization tool which can probe elemental, chemical, magnetic and electronic properties at nanoscale resolutions would be powerful tool to examine the functional films. XTIP beamline at Advanced Photon Source is the world first dedicated beamline for Synchrotron X-ray Scanning Tunneling Microscopy (SX-STM) to study nanomaterials with unprecedented details. The technique employs atomically sharp tip as a detector and detect surface sensitive signals. Here we present, studies conducted at XTIP beamline to probe ferroelectric thin films, multielement alloys and nanocluster catalytic systems. The capability to explore chemical and electronic states of functionalized films at high spatial resolution enables to study localized surface chemistry.

Linking Defects with Electronic Structure, and Optoelectronic Properties in Semiconductor Thin Films: Emila Panda1; 1IIT Gandhinagar
    Electronic structure and optoelectronic properties of a semiconductor are found to be highly sensitive to its overall microstructure and electronic defect states, which in turn depends on the synthesis route as well as process parameters used for its fabrication. It is also equally important to understand the (variation in the) surface defect states and surface electronic structure as these films are always present in a stack, influencing the electrical properties of the next layers and thus the entire device. To this end, several oxide- and sulfide-based semiconducting materials (more specifically, doped ZnO, doped anatase TiO2, Cu2S and SnS) are addressed in this presentation. Moreover, this talk will discuss a systematic interrelation between the defects, electronic structure, and optoelectronic properties of these materials with respect to the (non-equilibrium) synthesis techniques and process parameters, which are important to fabricate optimized device-quality material.

Surrogates for Actinide Thin Film Research: Ashutosh Tiwari1; Cody Dennett2; Narayan Poudel2; Krzysztof Gofryk2; 1University of Utah; 2Idaho National Lab
    In this talk we will present some of our work related to rare earth (RE) oxide-based materials that can be used as surrogates for actinides. REs have quite similar physical and chemical properties as actinides and are not radioactive. REs can therefore be used as a surrogate for actinides in experimental studies focused on gaining fundamental understanding of important physical mechanisms undergoing in these systems.

Two-photon Lithography of 2D/3D Nanostructures in Polymer and Composite Matrix: Shobha Shukla1; 1IIT Bombay
    Nonlinear absorption processes based on multi photon absorption can be utilized for making true 3 dimensional structures. Here, we will discuss limitations, bottlenecks and ways to address some of the issues of two-photon lithography for making function nano and micro structures. Free standing, two-three dimensional subwavelength features in polymeric and composite matrix will not only allow lab on a chip but also pave way for integration of photonic components on silicon based chips. Femtosecond laser based microfabrication is scalable and can be used to manufacture large volumes of micro- and nanostructures quickly and inexpensively.

Transient Laser Heating Induced Nanoscopic Surface Reconstruction in VO2 Thin Film: Soumya Mandal1; Adele Moatti2; Jagdish Narayan2; Ritesh Sachan1; 1Oklahoma State University; 2North Carolina State University
    This work presents a detailed study on atomic rearrangements and structural transformations via ultrafast melting and quenching in VO2 thin film by nanosecond pulsed laser irradiation. Using atomic-resolution electron microscopy, we observe that laser irradiation induces a surface reconstruction in VO2. Interestingly, the change in stoichiometry-induced orbital occupancy causes the reduction in relative resistivity of recrystallized VO2 by one order of magnitude. By performing atomic distance mapping with atomic-resolution images, we estimate ~0.031 nm and ~0.013 nm atomic displacement as compared to the pristine lattice along the out-of-plane and in-plane direction, respectively. Electron energy-loss spectroscopy analysis confirms the shift in O-K and O-prepeak and change in V-L2,3 ratios (~1.06 to 1.12) across the interface. These results explain the systematic modification of orbital occupancy, which attributes to the metallic characteristics in VO2. Overall, this study offers a critical understanding of structure-property correlations in VO2 through surface modification via pulsed laser irradiation.

Tailoring the Properties of Carbon Thin Films on Flexible HDPE Substrate by Non-equilibrium Laser Annealing: Pratik Joshi1; Parand Riley1; Roger Narayan1; Jagdish Narayan1; 1North Carolina State University
    Adherent carbon coatings on flexible polymeric substrates are necessary for state-of-the-art flexible electronic and health monitoring applications. Highly adherent Si-containing DLC films have been fabricated on flexible HDPE substrates using plasma-enhanced chemical vapor deposition technique. Plasma etching makes the surface of HDPE flat and opens up the surface bonds. Scratch test reveals 10 mN as the critical load for coating particle removal. The TEM analysis also confirmed excellent DLC adhesion to film substrate. The contact angle for HDPE increased from 90o to 110o when it was coated with Si-DLC. Further, these amorphous carbon coatings showed improvement in the adhesion, hydrophobicity and electrical conductivity after non-equilibrium laser annealing due to an increase in the amount of sp2 bonded carbon. This study provides useful information for modifying the properties of carbon thin films on flexible polymers for desired applications.