Information Storage Technology Research Articles

Surface weak ferromagnet coupling induced giant room-temperature spontaneous exchange bias in antiferromagnet Fe3BO6 polycrystals.

The spontaneous exchange bias effect (SEB) has wide application prospects in information storage technologies. In this study, nanoscale raw materials were used to fabricate antiferromagnetic Fe3BO6 polycrystals. The obtained Fe3BO6 exhibited a large SEB effect, where the value of the spontaneous exchange bias field at room temperature was as large as ∼4234 Oe. The room-temperature training effect, temperature-dependence, and maximum field-dependence of the HSEB were investigated. We propose that this giant SEB originates from the exchange-coupling interactions between the weak ferromagnetic surface state and the bulk antiferromagnetic state. The theoretical analysis results were further verified by comparing the magnetic properties of the Fe3BO6 with relatively low crystallinity. The results of this investigation will help find promising candidate materials for devices based on the SEB effect.

Laser assembly of CeO2 nanobrushes and their resistive switching performance

Memristors in a metal/oxide/metal configuration emerge as an advanced non-volatile information storage technology due to their high operating speed and low power consumption. Understanding the role of the microstructure of the active oxide layer in its resistive switching (RS) performance is scientifically important for revealing the conduction mechanism of oxides, and technically critical for the development of high-performance memristors. Here, self-assembly of vertically aligned CeO2 nanobrushes, a typical RS material, is demonstrated in pulsed laser epitaxy. The growth map of CeO2 is fully explored, and optimized growth conditions for CeO2 nanobrushes are established. Microstructure and crystallinity characterizations reveal the single-crystalline epitaxy nature of CeO2 nanobrushes. A nanobrush memristor exhibits a threshold switching feature with an On/Off ratio of 50, as 16 times high as a thin-film memristor, and excellent endurance of up to 500 cycles and retention time of up to 104 seconds. Theoretical fitting of the I-V curves of the thin-film and nanobrush memristors show interfacial switching in the thin-film memristor and filamentary switching in the nanobrush memristor. The distinct RS mechanisms between thin films and nanobrushes suggest the fundamental role of the structural design of active oxide layers in the RS performance of oxide-based memristors.

Wafer-level flexible carbon-based film for fluorescent display and optical information storage

Fluorescent materials have garnered significant interest in optical display and information storage fields for their vibrant and distinct color presentation. Extensive research has been conducted on carbon-based fluorescent materials owing to their environmental sustainability, versatility, and adjustable optical properties. However, it is difficult to integrate high-resolution fluorescent structure on various wafer-level substrate for abundant optical display and information storage. This study successfully fabricated wafer-level carbon-based fluorescent flexible film with ∼100 μm thick using a standardized “lithography + annealing” process. The sample demonstrates high fluorescence intensity with a peak at 603 nm and fluorescence lifetime of 0.3517 ns. When excited by light of 365 nm, 485 nm, and 525 nm wavelengths, the film displays yellow, green, and red, showcasing exceptional color tuning capability. This flexible film is portable and can be readily integrated with various substrates, offering significant technical and theoretical support for advancing carbon-based optical display and information storage technologies.

Spin Transport Modulation of 2D Fe3O4 Nanosheets Driven by Verwey Phase Transition.

Realizing spin transport between heavy metal and two-dimensional(2D) magnetic materials at high Curie temperature (TC) is crucial to advanced spintronic information storage technology. Here, environmentally stable 2D nonlayered Fe3O4 nanosheets are successfully synthesized using a reproducible process and found that they exhibit vortex magnetic domains at room temperature. A Verwey phase transition temperature (TV) of ≈110 K is identified for ≈3nm thick nanosheet through Raman characterization and spin Hall device measurement of the Pt/Fe3O4 bilayer. The anisotropic magnetoresistance ratio decreases near TV, while both the spin Hall magnetoresistance ratio and spin mixing conductance (Gr) increase at TV. As the temperature approaches 112 K, the anomalous Hall effect ratio tends to become zero. The maximum Gr reaches ≈5 × 1015 Ω-1m-2 due to the clean and flat interface between Pt and 2D nanosheet. The observed spin transport behavior in Pt/Fe3O4 spin Hall devices indicates that 2D Fe3O4 nanosheets possess potential for high-power micro spintronic storage devices applications.

Spatially Resolved Light-Induced Ferroelectric Polarization in α-In2Se3/Te Heterojunctions.

Light-induced ferroelectric polarization in 2D layered ferroelectric materials holds promise in photodetectors with multilevel current and reconfigurable capabilities. However, translating this potential into practical applications for high-density optoelectronic information storage remains challenging. In this work, an α-In2Se3/Te heterojunction design that demonstrates spatially resolved, multilevel, nonvolatile photoresponsivity is presented. Using photocurrent mapping, the spatially localized light-induced poling state (LIPS) is visualized in the junction region. This localized ferroelectric polarization induced by illumination enables the heterojunction to exhibit enhanced photoresponsivity. Unlike previous reports that observe multilevel polarization enhancement in electrical resistance, the device shows nonvolatile photoresponsivity enhancement under illumination. After polarization saturation, the photocurrent increases up to 1000 times, from 10-12 to 10-9 A under the irradiation of a 520nm laser with a power of 1.69 nW, compared to the initial state in a self-driven mode. The photodetector exhibits high detectivity of 4.6×1010 Jones, with a rise time of 27 µs and a fall time of 28 µs. Furthermore, the device's localized poling characteristics and multilevel photoresponse enable spatially multiplexed optical information storage. These results advance the understanding of LIPS in 2D ferroelectric materials, paving the way for optoelectronic information storage technologies.

Magnetoelectric effects in magnetic films with alternating magnetic anisotropy: the emergence and stability of Bloch points.

Magnetic topological states are a subject of intense investigation due to their potential for advancing scalable logic and information storage technologies. In this article, we investigate topological defects in magnetic films, focusing on Bloch point-like singularities in magnetization distribution with significant implications for magnetoelectric and ferroelectric properties. We explore exchange-coupled ferromagnetic films composed of alternating magnetic layers with distinct in-plane and out-of-plane magnetic anisotropy. Through micromagnetic simulations, we analyze the magnetization reversal processes and the emergence of Bloch point-like configurations induced by external magnetic fields. We identify the conditions necessary for stabilizing these states and elucidate their ferroelectric properties. Our study reveals that Bloch points act as sources of electrical charge due to the inhomogeneous distribution of magnetization, offering opportunities for implementing their electric properties in future devices.

Phonon-mediated infrared plasmonic metamaterial emitters towards high-capacity multifunctional encoding and display.

This study introduces what we believe is a novel approach to manipulating light in the mid-infrared spectrum through phonon-mediated metal-insulator-metal (MIM) cavities. Leveraging the unique interactions between resonantly excited electric and magnetic dipoles and phonons within silicon dioxide spacers, we have developed a technology different from traditional methods that rely on geometric modifications of nanostructures, offering a more versatile and effective means of tailoring light-matter interactions at the nanoscale. Our experimental results showcase the ability of these MIM cavities to perform multifunctional information encoding, display, and concealment with high precision. Notably, we encoded 13 distinct gray levels, surpassing previous capabilities in the long-wave infrared spectrum using metamaterial emitters. Furthermore, the incorporation of rotating nanorod structures enabled the encoding of grayscale patterns through polarization states, enhancing the potential for high-capacity information storage. The study also demonstrates the capability of these structures for subwavelength-resolution printing and near-diffraction-limit information encoding in the long-wave infrared band. We have successfully employed an innovative ink coating method, transparent in the long-wave infrared but opaque in the visible spectrum, to conceal encoded information, thereby adding a layer of security. In summary, the phonon-mediated infrared plasmonic metamaterial emitters presented in this work pave the way for future research in high-capacity information storage, anti-counterfeiting, and security technologies.

Challenges for exploiting nanomagnet properties on surfaces.

Molecular complexes with single-molecule magnet (SMM) or qubit properties, commonly called molecular nanomagnets, are great candidates for information storage or quantum information processing technologies. However, the implementation of molecular nanomagnets in devices for the above-mentioned applications requires controlled surface deposition and addressing the nanomagnets' properties on the surface. This Perspectives paper gives a brief overview of molecular properties on a surface relevant for magnetic molecules and how they are affected when the molecules interact with a surface; then, we focus on systems of increasing complexity, where the relevant SMMs and qubit properties have been observed for the molecules deposited on surfaces; finally, future perspectives, including possible ways of overcoming the problems encountered so far are discussed.

Understanding Antiferromagnetic Coupling in Lead-Free Halide Double Perovskite Semiconductors.

Solution-processable semiconductors with antiferromagnetic (AFM) order are attractive for future spintronics and information storage technology. Halide perovskites containing magnetic ions have emerged as multifunctional materials, demonstrating a cross-link between structural, optical, electrical, and magnetic properties. However, stable optoelectronic halide perovskites that are antiferromagnetic remain sparse, and the critical design rules to optimize magnetic coupling still must be developed. Here, we combine the complementary magnetometry and electron-spin-resonance experiments, together with first-principles calculations to study the antiferromagnetic coupling in stable Cs2(Ag:Na)FeCl6 bulk semiconductor alloys grown by the hydrothermal method. We show the importance of nonmagnetic monovalence ions at the BI site (Na/Ag) in facilitating the superexchange interaction via orbital hybridization, offering the tunability of the Curie-Weiss parameters between -27 and -210 K, with a potential to promote magnetic frustration via alloying the nonmagnetic BI site (Ag:Na ratio). Combining our experimental evidence with first-principles calculations, we draw a cohesive picture of the material design for B-site-ordered antiferromagnetic halide double perovskites.

Topological Spin Textures in an Insulating van der Waals Ferromagnet.

Generation and control of topological spin textures constitutes one of the most exciting challenges of modern spintronics given their potential applications in information storage technologies. Of particular interest are magnetic insulators, which due to low damping, absence of Joule heating and reduced dissipation can provide energy-efficient spin-textures platform. Here, it is demonstrated that the interplay between sample thickness, external magnetic fields, and optical excitations can generate a prolific paramount of spin textures, and their coexistence in insulating CrBr3 van der Waals (vdW) ferromagnets. Using high-resolution magnetic force microscopy and large-scale micromagnetic simulation methods, the existence of a large region in T-B phase diagram is demonstrated where different stripe domains, skyrmion crystals, and magnetic domains exist and can be intrinsically selected or transformed to each-other via a phase-switch mechanism. Lorentz transmission electron microscopy unveils the mixed chirality of the magnetic textures that are of Bloch-type at given conditions but can be further manipulated into Néel-type or hybrid-type via thickness-engineering. The topological phase transformation between the different magnetic objects can be further inspected by standard photoluminescence optical probes resolved by circular polarization indicative of an existence of exciton-skyrmion coupling mechanism. The findings identify vdW magnetic insulators as a promising framework of materials for the manipulation and generation of highly ordered skyrmion lattices relevant for device integration at the atomic level.

Simulating selected magnetic properties of Tb x Pr1− x Al2, a magnetocaloric compound

Tb x Pr1−x Al2 are ferrimagnetic materials exhibiting magnetocaloric effect that have gained considerable attention due to their potential use as an alternative in refrigeration, magnetic sensors and in information storage technology. Here using the mean field approach numerical simulations were conducted for x = 0.1, 0.2, 0.3, 0.4, 0.5, and 0.75, to analyze selected physical properties, such as x-ray and neutron powder diffraction, magnetization and heat capacity. The simulations successfully reproduced the experimental data providing a comprehensive characterization and improved understanding of this family of compound.

The trade-off anionic modulation in metal-organic glasses showing color-tunable persistent luminescence.

Ultralong room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) materials provide exciting opportunities for the rational design of persistent luminescence owing to their long-lived excitons. However, conventional rare-earth-based all-inorganic emitters involve high cost and harsh synthesis conditions, and purely organic systems may require complicated synthesis routes and tedious purification. Therefore, it is highly desirable to develop a cost-effective and easily manufacturable method for achieving color-tunable RTP-TADF with a long afterglow. Herein, we demonstrate a rational strategy to introduce different anions (Cl-, Br- and OAc- ions) into a Zn-based metal-organic scaffold, which can improve the crystal rigidity and achieve a well-balanced RTP-TADF. Both theoretical and experimental studies have demonstrated that the adjustment of different anions can effectively modulate the spin-orbit coupling (SOC) and the energy gap of singlet-triplet states (ΔEST) and then tailor the afterglow lifetime. Moreover, we prepared dye-doped metal-organic hybrid glasses with remarkable potential for the color-tunable afterglow. Therefore, this work not only provides a new horizon for modulating crystal and glass states with color/lifetime-tunable persistent luminescence, but also contributes to optical information storage and anti-counterfeiting technology.

Endohedral metallofullerene molecular nanomagnets.

Magnetic lanthanide (Ln) metal complexes exhibiting magnetic bistability can behave as molecular nanomagnets, also known as single-molecule magnets (SMMs), suitable for storing magnetic information at the molecular level, thus attracting extensive interest in the quest for high-density information storage and quantum information technologies. Upon encapsulating Ln ion(s) into fullerene cages, endohedral metallofullerenes (EMFs) have been proven as a promising and versatile platform to realize chemically robust SMMs, in which the magnetic properties are able to be readily tailored by altering the configurations of the encapsulated species and the host cages. In this review, we present critical discussions on the molecular structures and magnetic characterizations of EMF-SMMs, with the focus on their peculiar molecular and electronic structures and on the intriguing molecular magnetism arising from such structural uniqueness. In this context, different families of magnetic EMFs are summarized, including mononuclear EMF-SMMs wherein single-ion anisotropy is decisive, dinuclear clusterfullerenes whose magnetism is governed by intramolecular magnetic interaction, and radical-bridged dimetallic EMFs with high-spin ground states that arise from the strong ferromagnetic coupling. We then discuss how molecular assemblies of SMMs can be constructed, in a way that the original SMM behavior is either retained or altered in a controlled manner, thanks to the chemical robustness of EMFs. Finally, on the basis of understanding the structure-magnetic property correlation, we propose design strategies for high-performance EMF-SMMs by engineering ligand fields, electronic structures, magnetic interactions, and molecular vibrations that can couple to the spin states.

Magnetic-field-controlled positioning of magnetic domain wall in tie-shaped asymmetric nanowire and its application for magnetic field detection.

With topological spin texture, magnetic domain walls have soliton-like dynamic behaviors in magnetic nanowires, which can be used in information transmission and storage technology. Therefore, precisely controlling the dynamic behavior of the magnetic domain wall and its pinning behavior is one of the important technical challenges in realizing domain-wall-based spintronic devices. In this work, a geometrically defect-free scheme for domain wall pinning/depinning is proposed using micromagnetic simulations based on a tie-shaped asymmetric nanowire, which can precisely control the position of the magnetic domain wall in an external magnetic field. The results show that the domain wall in tie-shaped nanowires exhibits excellent linear response and ultrafast time response to external magnetic fields, which endow them with potential applications for high-frequency weak-magnetic-field detection. We further propose a scheme for constructing a magnetic-field sensor using the tie-structured nanowire, and we study its feasibility.

A novel viologen-based hybrid crystalline material for photochromic glass films, information storage and anti-counterfeiting.

Information storage and anti-counterfeiting are two very important applications of photochromic materials. Photochromic materials with both information storage and anti-counterfeiting should meet the requirements including fast coloration, good stability and reversibility, low storage cost, and practical application value. Herein, a novel viologen-based coordination polymer, Cd[(pbpy)0.5(HBTC)Cl]·2H2O (1) (pbpy = 1,1'-[1,4-phenylenebis-(methylene)]bis(4,4'-bipyridinium); HBTC2- = 1,3,5-benzenetricarboxylic acid), has been constructed. Compound 1 not only exhibits selective amine sensing properties, but also shows excellent photochromic properties, and the anti-counterfeiting of a two-dimensional code can be also realized through the color-changing behavior. Meanwhile, photochromic glass films of compound 1 were prepared, and compared to traditional optical information storage technology, these photochromic glass films have better water resistance and stability, improving their practical application stability. This work has further enriched the application of photochromic materials in the field of sensing, anti-counterfeiting and information storage.

Circular dichroism in two-dimensional BC6N and B3C2N3 in absence of intervalley excitonic coupling

Two-dimensional (2D) noncentrosymmetric systems offer potential opportunities for exploiting the valley degrees of freedom for advanced information processing, owing to non-zero Berry curvature. However, such valley polarization in 2D materials is crucially governed by the intervalley excitonic scattering in momentum space due to reduced electronic degrees of freedom and consequent enhanced electronic correlation. Here, we study the valley excitonic properties of two 2D noncentrosymmetric complementary structures, namely, BC6N and B3C2N3 using first principles-based GW calculations combined with the Bethe–Salpeter equation, that brings the many-body interactions among the quasiparticles. The k-resolved oscillator strength of their first bright exciton indicates their ability to exhibit valley polarization under the irradiation of circularly polarized light of different chiralities. Both the systems show significant singlet excitonic binding energies of 0.74 eV and 1.31 eV, respectively. Higher stability of dark triplet excitons as compared to the singlet one can lead to higher quantum efficiency in both the systems. The combination of large excitonic binding energies and the valley polarization ability with minimal intervalley scattering make them promising candidates for applications in advanced optical devices and information storage technologies.

Chemo-Triggered luminescence of sulfur nanoparticles for highly secure information storage

Most of the information storage technologies that rely solely on the luminous signals of specific materials may be cracked and forged. It is always a technical challenge that special “keys” are used to trigger luminescent material for encryption. In this paper, green fluorescent quantum dots (green SQDs) were synthesized by utilizing the corrosion and encapsulation functions of polyethyleneimine (PEI). Green SQDs transform into blue SQDs under the stimulation of H2O2. Stimulus-responsive characterization of green SQDs was used for highly secure message encryption. This work provides a promising application in the field of high-security information storage for chem-triggered luminescent materials.

Research and design of student archives management system based on consortium blockchain

Student archives are records of students’ learning activities during school and important proof of students’ learning experiences, so the construction of a credible digital archives system is of great significance. Blockchain is a data structure and information storage technology that has become well-known with the development of Bitcoin and is currently widely used to build a trusted digital environment. The use of blockchain technology can solve the problems of low confidentiality and easy tampering of traditional archives management. Therefore, this paper proposes a blockchain-based student archives management scheme, designs the key data structures and algorithms of the system model, and tests the functions and performance of the system model on the ESXi platform. Experimental results show that the scheme proposed in this paper can effectively improve the confidentiality and difficulty of archive tampering, and at the same time have good resource sharing and retrieval efficiency, making archives management safer, more credible and more intelligent.

System construction of deep learning AI cloud service mode

Deep learning (DL) is the basis of many applications of artificial intelligence (AI), and cloud service is the main way of modern computer capabilities. DL functions provided by cloud services have attracted great attention. At present, the application of AI in various fields of life is gradually playing an important role, and the demand and enthusiasm of governments at all levels for building AI computing capacity are also growing. The AI logic evaluation process is often based on complex algorithms that use or generate large amounts of data. Due to the higher requirements for the data processing and storage capacity of the device itself, which are often not fully realized by humans because the current data processing technology and information storage technology are relatively backward, this has become an obstacle to the further development of AI cloud services. Therefore, this paper has studied the requirements and objectives of the cloud service system under AI by analyzing the operation characteristics, service mode and current situation of DL, constructed design principles according to its requirements, and finally designed and implemented a cloud service system, thereby improving the algorithm scheduling quality of the cloud service system. The data processing capacity, resource allocation capacity and security management capacity of the AI cloud service system were superior to the original cloud service system. Among them, the data processing capacity of AI cloud service system was 7.3% higher than the original cloud service system; the resource allocation capacity of AI cloud service system was 6.7% higher than the original cloud service system; the security management capacity of AI cloud service system was 8.9% higher than the original cloud service system. In conclusion, DL plays an important role in the construction of AI cloud service system.

How to Create Business Value Through Technological Innovations Using ICCT Underlying Technologies

Purpose: Organizations are struggling to sustain and grow in the 21st century due to many challenges and uncertainties while doing their business. Long-term sustaining in the business needs retaining the existing customers and attracting new customers through various strategies for satisfying, delighting, and enlightening existing customers, and creating overwhelming demand through business value creation for attracting new customers. It is a challenge for all the decision-makers to find out how to create business value to retain existing customers and attract new customers. Here, a conceptual and exploratory analysis is made of how the innovations using technology create business value for organizations in general. Methodology: This conceptual analysis uses an exploratory research method. The information is collected using Google, Google Scholar, and Artificial Intelligence GPT search engines using appropriate keywords and prompt engineering respectively and the collected, analysed, compared, evaluated, and interpreted towards creating business value using technology with special emphasis on the use of ICCT underlying technologies. The advantages, benefits, constraints, and disadvantages of business value creation using ICCT underlying technologies for business value creation are listed from stakeholders’ points of view. Outcome: The role of twelve ICCT Underlying Technologies including AI, Blockchain, Business intelligence, Cloud computing, Cyber security, 3D printing, IoT, Quantum computing, Mobile marketing, Information storage technology, Ubiquitous education technology, and VR & AR for Business Value Creation like Innovation and Differentiation, Customer focus, Operational efficiency, Strategic Partnerships and Alliances, Talent Management, Effective Marketing and Branding, Financial Performance and Growth, Sustainability and Corporate Social Responsibility, and Adaptability and Agility. Originality/Value: New knowledge and interpretation are presented on how to create business value for long time sustainability by organizations in every industry. Type o Paper: Exploratory Research Analysis