Himanshu Jain

Lehigh University · Department of Materials Science and Engineering

The donor-acceptor interaction of a charge-coupled heterostructure encompassing a metal and an amorphous semiconductor subjected to a laser field has many potential applications in the realm of nonlinear optics. In this work, we fabricate an electron donor gold nanoparticle (AuNP) and acceptor amorphous Ge 24 Se 76 hetero-structure on a quartz subs...

The donor-acceptor interaction of a charge-coupled heterostructure encompassing a metal and an amorphous semiconductor subjected to a laser field has many potential applications in the realm of nonlinear optics. In this work, we fabricate an electron donor gold nanoparticle (AuNP) and acceptor amorphous Ge24Se76 heterostructure on a quartz substrat...

The mechanism of non-congruent growth of a crystal from glass has been sought using molecular dynamics simulations. Specifically, as a model of this process, the growth of a lithium niobate (LiNbO3) crystal seed sandwiched between two lithium niobosilicate (LNS) glass slabs has been simulated as a function of time and temperature. The growth of pre...

Laser heating is well-established to impart optical functionality into glass by local modification and crystallization. In this paper, we demonstrate electron beam heating in scanning and transmission microscopes as an alternative for the local crystallization of Sb2S3 in Sb-S-I glasses as a model system. Governed by different absorption physics, t...

Spatially selective growth of lithium niobate (LiNbO3) crystals deep within lithium niobosilicate (LNS) glass can be achieved via femtosecond laser irradiation, wherein these crystals could serve as optical elements in photonic integrated circuits. In practice, it is challenging to achieve continuous, single-crystal growth of LiNbO3 within LNS glas...

A partial charge empirical potential for the Nb-O pair has been developed based on existing parameters of other pairs in a Teter potential to enable molecular dynamics simulations of both lithium niobate crystal and lithium niobosilicate glasses. The developed potential is capable of describing structural features of lithium niobosilicate glasses i...

Purpose Titanium is commonly used for implants because of its corrosion resistance and osseointegration capability. It is well known that surface topology affects the response of bone tissue towards implants. In vivo studies have shown that in weeks or months, bone tissue bonds more efficiently to titanium implants with rough surfaces compared to s...

Atomic arrangements systemically deviating from the classic definition of single crystal lattice have been known in spherulites for over a century. However, their unusual curved lattice could not be exploited for useful applications due to their uncontrolled orientations and lattice curvatures. Heating of glass with focused laser, electron, or X‐ra...

Advances in developing high entropy alloys and ceramics with improved physical properties have greatly broadened their application field from aerospace industry, public transportation to nuclear plants. In this review, we describe the concept of entropy engineering as applicable to inorganic non-metallic glasses, especially for tailoring and enhanc...

The effects of cooling rate on the structure and properties of lithium disilicate (LS2) glass are investigated using molecular dynamics (MD) computer simulations. The evolution of structural features such as pair distribution function, bond angle distribution, and Li coordination distribution are determined, and correlated with dynamic and static p...

In an effort to verify whether the Ovonic threshold switching in amorphous chalcogenide film is concomitant with any noticeable atomic rearrangements, we analyze EXAFS spectra of amorphous chalcogenide Ge60Se40 (at%) film measured in situ under DC electric field. The in situ EXAFS measurements are performed with specifically prepared specimens, in...

To understand the unique physical properties of Ga‐Sb‐Se glasses, high‐resolution XPS studies have been performed on representative compositions within the glass‐forming region. The observed peaks in the valence band as well as in Ga, Sb and Se core level XPS spectra are related to the main structural building blocks of the covalent network. On the...

The nanostructure of engineered bioscaffolds has a profound impact on cell response, yet its understanding remains incomplete as cells interact with a highly complex interfacial layer rather than the material itself. For bioactive glass scaffolds, this layer comprises of silica gel, hydroxyapatite (HA)/carbonated hydroxyapatite (CHA), and absorbed...

Laser heating can be used to produce single crystal architectures in glass with a lattice that rotates at a constant rate. Such metamaterials can offer properties that are disallowed by conventional crystal structures. To establish the mechanism of this lattice rotation, we used transmission electron microscopy (TEM) to directly observe and charact...

Introduction/Objective The tailored amorphous multi-porous (TAMP) material fabrication technology has led to a new class of bioactive materials possessing versatile characteristics. It has not been tested for dental applications. Thus, we aimed to assess its biocompatibility and ability to regenerate dental mineral tissue. Methods 30CaO-70SiO2 mod...

Thermal poling is a widely used method for creating glass surfaces with modified structure and altered properties by application of DC voltage. The mechanism of structural change has remained controversial, especially as poling is performed well below the glass transition temperature. Specifically, the role of Joule heating in facilitating structur...

Single crystal LaBGeO 5 architecture formed in La 2 O 3-B 2 O 3-2GeO 2 glass serves as a model system for understanding of the transformation from glass to single crystal under fs laser irradiation. This transformation is highly sensitive to glass composition, raising the need to understand how the glass structure and composition evolve during crys...

Laser heating of chalcogenide glasses has successfully produced rotating lattice single crystals through a solid-solid transformation. To better understand the nature of complex, orientation-dependent lattice rotation, we designed heat profiles of the continuous wave laser by beam shaping, fabricated larger Sb2S3 crystal dots in Sb2S3 glass, and in...

Glass‐to‐crystal transformation of lithium disilicate is studied using molecular dynamics simulations using an effective partial charge potential. The structural evolution of the interface between glassy and crystalline lithium disilicate is analyzed to simulate crystallization of glass on pre‐existing crystal seeds. Besides previously used atomic...

Kinetics of physical aging in archetypic 45S5 bioactive silicate glass composition with different types of phase separation are studied in situ below the glass transition temperature (Tg). The qualitative nature of aging is found to be almost independent of the structural differences on the micrometer scale. A well-expressed step-like behaviour in...

Single crystal architectures in glass, formed by a solid‐solid transformation via laser heating, are novel solids with a rotating lattice. To understand the process of lattice formation that proceeds via crystal growth, we have observed in‐situ Sb2S3 crystal formation under x‐ray irradiation with simultaneous Laue micro X‐ray diffraction (μXRD) pat...

Localized controlled heating of glass with a continuous wave laser has introduced the possibility of engineering the lattice of recently discovered rotating lattice single (RLS) crystals, and thus obtain novel metamaterials. Towards this goal, we report the role of laser scanning speed on the lattice structure of a model system: Sb2S3 straight RLS...

Photoinduced expansion is a special property of chalcogenide glasses, which makes them useful for various applications in photonics. A clear understanding of the kinetics and the topography of photoinduced effects is fundamental to improve potential applications. A detailed study on bulk glass is performed using in situ Atomic Force Microscope meas...

Practical applications of the recently demonstrated method of growing single crystal architecture in glass by femtosecond laser demand answers to two key questions: 1. How is the formation of a single crystal affected by the incongruent composition of glass? 2. Why are laser scanning speeds higher than a critical value necessary for obtaining singl...

Fabrication of single crystals of materials by conventional methods, which decompose or undergo incongruent melting upon melting, has limited the development of advanced technologies. A solution to this challenge was demonstrated a few years ago using laser heating in a localized region to minimize undesirable nucleation, and then scanning the beam...

According to Joule’s well-known first law, application of electric field across a homogeneous solid should produce heat uniformly in proportion to the square of electrical current. Here we report strong departure from this expectation for common, homogeneous ionic solids such as alkali silicate glasses when subjected even to moderate fields (~100 V...

Ferroelectric single-crystal-architecture-in-glass is a new class of metamaterials that would enable active integrated optics if the ferroelectric behavior is preserved within the confines of glass. We demonstrate using lithium niobate crystals fabricated in lithium niobosilicate glass by femtosecond laser irradiation that not only such behavior is...

Nanosheet-nanowire heterostructure provides a new platform to explore the nonlinear optical phenomena at the nanoscale. In this article, we report giant nonlinear absorption (NLA) coefficient ≈0.94 × 103 cm/GWat 1064 nm and 0.64 × 103 cm/GW at 532 nm in a new type of heterostructure of two-dimensional graphene oxide (GO) nanosheets and one-dimensio...

To understand the unique features of germanium sulfide (~60–70 at.% of S) glasses modified with Ga or Sb, the chemical order in these materials is investigated using X-ray photoelectron spectroscopy (XPS). The obtained results are correlated with Raman spectroscopy data and verified with quantum chemical calculations. It is shown that in addition t...

For hard tissue regeneration, the bioactivity of a material is measured by its ability to induce the formation of hydroxyapatite (HA) under physiological conditions. It depends on the dissolution behavior of the glass, which itself is determined by the composition and structure of glass. The enhanced HA growth on nanoporous than on nonporous glass...

Chalcogenide glass – silver heterostructures are candidates for photoresist and diffractive optical applications. To optimize their processing, we report the kinetics of Ag photo-dissolution in As2S3 matrix using in-situ optical transmission/reflection measurements and real time atomic force microscopy (AFM) imaging under optical illumination. The...

Chalcogenide glass-silver heterostructures are candidates for photoresist and diffractive optical applications. To optimize their processing, we report the kinetics of Ag photo-dissolution in As2S3 matrix using in-situ optical transmission/reflection measurements and real time atomic force microscopy (AFM) imaging under optical illumination. The re...

Chalcogenide glass-silver heterostructures are candidates for photoresist and diffractive optical applications. To optimize their processing, we report the kinetics of Ag photo-dissolution in As2S3 matrix using in-situ optical transmission/reflection measurements and real time atomic force microscopy (AFM) imaging under optical illumination. The re...

Tissue regeneration is a significantly improved alternative to tissue replacement by implants. It requires porous bioscaffolds for the restoration of natural tissue rather than relying on bio-inactive, often metallic implants. Recently, we developed technology for fabricating novel, nano-macroporous bioactive 'Tailored Amorphous Multi-Porous (TAMP)...

A carefully controlled femtosecond laser irradiation offers the possibility of fabricating high quality, 3D functional single-crystal patterns designed for integrated optical devices deep inside glass. Notwithstanding, a general theory relating particular irradiation conditions to crystal growth dynamics and resulting morphologies remains to be est...

We demonstrate how the special environment for crystal growth in glass that are imposed by a laser can lead to rotation of the crystal lattice within a crystal and present potential applications

Electric field-induced softening (EFIS) is a recently discovered phenomenon leading to significant reduction in the furnace temperature at which glass softens under the application of DC voltage. Unfortunately, it is accompanied by local compositional changes due to migration of ions that could limit its usefulness. To overcome this drawback, we ha...

We have investigated the occurrence of the sometimes observed grain boundaries, as initial seed is extended to form line in laser-fabricated single-crystal architecture in glass (SCAG). In particular, for Sb2S3 SCAG in Sb-S-I glass as a model system, grain boundaries are formed during the transition from laser-written initial seed dot to crystal li...

Three-dimensional laser-induced crystallization of glass via localized heating by focused femtosecond laser irradiation promises the ability to create photonic integrated circuits. However, little work thus far has been done to demonstrate the feasibility of this technique to create crystals in rare earth-doped glasses that may serve as active elem...

We have investigated photoinduced effects in as-deposited Ge40-xSbxSe60 (x=8, 15, and 20) films via in situ measurements of transmission spectra for wavelengths λ=500 to 950nm. The absorption coefficient increases initially, indicating the photodarkening (PD) effect, which rapidly saturates in tens of seconds. Then the absorption coefficient starts...

We analyzed the biological performance of spinodally and droplet-type phase-separated 45S5 Bioglass® generated by quenching the melt from different equilibrium temperatures. MC3T3-E1 pre-osteoblast cells attached more efficiently to 45S5 Bioglass® with spinodal than to the one with droplet morphology, providing the first demonstration of the role o...

Electric field-induced softening (EFIS) has been suggested as an innovative glass processing technique to reduce the furnace temperature required for softening of alkali silicate glasses. Although its overall mechanism was proposed previously, further investigation is required to fully understand the beginning of the EFIS process from initial polar...

Lithium niobate crystals were grown in 3D through localized heating by femtosecond laser irradiation deep inside 35Li2O-35Nb2O5-30SiO2 glass. Laser scanning speed and power density were systematically varied to control the crystal growth process and determine the optimal conditions for the formation of single crystal lines. EBSD measurements showed...

A rotating lattice single (RLS) crystal is a unique form of solid, which was fabricated recently as 1D architecture in glass via solid state transformation induced by laser irradiation. In these objects, the lattice rotates gradually and predictably about an axis that lies in the plane of the line and is normal to the laser scanning direction. This...

We have investigated the role of charge state of Ti in the electronic properties and structure of electrically conductive CMAS-TiO2-Pd glass and glass-ceramics by X-ray photoelectron spectroscopy, electron paramagnetic resonance, positron annihilation lifetime spectroscopy, and fluorescence spectroscopy. These studies suggest the concentration of T...

Chalcogenide glass (ChG) thin films prepared by solution based deposition technique offer important advantages over vacuum deposited films, which are useful for many applications especially in infrared optics. Their fabrication, which comprises dissolving the ChG in volatile organic solvent and then depositing thin film by spin coating the solution...

To facilitate hard tissue regeneration there is a pressing need to develop biocompatible, macroporous (pore size ∼100's of μm) scaffolds that are tailored ideally to suit individual patient needs. A critical requirement of this goal is that the scaffolds degrade in the body at a rate that is comparable to that of the tissue re-growth. Among various...

Defying the requirements of translational periodicity in 3D, rotation of the lattice orientation within an otherwise single crystal provides a new form of solid. Such rotating lattice single (RLS) crystals are found, but only as spherulitic grains too small for systematic characterization or practical application. Here we report a novel approach to...

Photostructural transformations within AsxS100-x (x = 30, 33, 35, 40) thin films upon exposure to LED light of different wavelengths, in both air and argon environments have been studied by high resolution XPS, Raman spectroscopy and LEIS methods. These complementary results show that light of energies close to the band gap does not modify chemical...

This study was designed as a split-mouth randomized controlled clinical trial to evaluate the effects of a novel bioactive glass scaffold—tailored amorphous multiporous (TAMP)—for the preservation of alveolar bone following tooth extraction in class II orthodontic patients. TAMP scaffolds were prepared and sterilized. Patients were screened for eli...

Metal nanoparticle-semiconductor interfaces are sites of complex light-matter interactions, in particular, the exciton-plasmon coupling which plays a key role in the optical response of such heterostructures. There exists a pathway of photoinduced charge transfer from the semiconductor to the metal, which can be used to controllably vary the drivin...

We have sought the structural origin of the recently reported electrical conductivity of lithium copper phosphate glass system (50-x) Li2O-xCu2O-50 P2O5, as lithium oxide is gradually replaced by Cu2O. The structure of these glasses was determined by X-ray photoelectron spectroscopy, Fourier Transform Infrared Spectroscopy and Raman spectroscopy. T...

Thermal energy storage has the potential to make electricity generation using solar energy possible any time of the day at competitive costs. Research toward improving the cost and efficacy of thermal energy storage systems is ongoing at several research centers. In particular, latent heat thermal energy storage systems offer the ability to store l...

Electro-thermal poling of alkali-containing glasses has been known to enhance various physical and chemical properties due to the formation of an alkali ion depletion layer. We have investigated the role of alkali ion migration in depletion layer formation by in situ impedance spectroscopy, poling current measurements and ToF-SIMS on two binary alk...

EXAFS analysis is performed on equiatomic GeSe and GeTe films to elucidate changes in the local atomic environments induced by crystallization. It reveals for both the films that the 4:2 configuration dominates in their as-deposited amorphous state. In their crystallized state, however, the 3:3 configuration prevails together with quasi-crystalline...

Many advanced technologies have relied on the availability of single crystals of appropriate material such as silicon for microelectronics or superalloys for turbine blades. Similarly, many promising materials could unleash their full potential if they were available in a single crystal form. However, the current methods are unsuitable for growing...

Low-Energy Ion-Scattering (LEIS) spectroscopy is a technique with a unique sensitivity to the elemental composition of the top atomic layer of a solid surface. LEIS measurements of ternary silicate glasses modified with Na2O, Cs2O, CaO, and BaO show that the compositions of the as-cast (melt) surface and the in-vacuum fracture surface often differ....

Ultrafast exciton-plasmon interaction in a-Ge24Se76/gold nanoparticles was studied. In the strong coupling regime, we report the first observation of the spectral narrowing of transient absorption that is accompanied by the onset suppression of plasmon absorption.

Effect of simultaneous Ga and Te addition on the structure of As 2 Se 3 glasses is studied using X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS) and Raman techniques. It is shown that most of As, Se and Te atoms build a covalent network according to their main valences. Threefold coordinated As atoms form py...

Motivated by the advantages of two-electrode flash sintering over normal sintering, we have investigated the effect of an external electric field on the viscosity of glass. The results show remarkable electric field-induced softening (EFIS), as application of DC field significantly lowers the softening temperature of glass. To establish the origin...

Chalcogenide glass thin layers are useful to many practical applications especially for the fabrication of infrared (IR) optical elements. In comparison to the conventional vacuum deposition methods of their preparation, recently chemical methods such as spin coating are gaining attention. They involve dissolution of the source bulk glass in approp...

Spin-coating technology offers a convenient method for fabricating photostable chalcogenide glass thin films that are especially attractive for applications in IR optics. In this paper we report the structure of spin-coated AsxS100 − x (x = 30, 35, 40) thin films as determined using high resolution X-ray photoelectron spectroscopy (XPS) and Raman s...