This paper reviews past developments and present understanding of the glass-forming ability, structure and physical, chemical, mechanical and magnetic properties of bulk glassy alloys (BGA) with the ...emphasis on recent results obtained since 1990, together with applications of BGA, achieved mainly in Tohoku University. After introducing the fundamental concepts around glassy alloys (GA) in Sections
1 and 2 describes the progress of the study of structural relaxation leading to the discovery of GA with a large supercooled liquid region. Section
3 reviews the history of BGA development, followed by BGA systems and their features in Section
4, and features of glassy structure in Section
5. Sections
6–9 summarize the engineering and standardization of Zr-based BGA, followed by the origins of the development of useful materials on the basis of experimental data on the compositional effect on the fundamental properties of basic ternary and quaternary Zr-based BGA. Sections
10 and 11 include the glass-forming ability and dynamic mechanical properties of Zr-based hypoeutectic BGA and Cu–Zr–Al–Ag BGA. Mechanical properties of Ni- and Zr-based BGA at low temperatures are shown in Section
12, while Section
13 describes the formation and properties of Ni-free Ti-based BGA. Sections
14 and 15 deal with porous Zr-based BGA, including spherical pores and commercialized ferromagnetic and high-strength Fe-based GA, respectively, then Section
16 reviews supercooled liquid formation. Applications for Zr-, Ti- and Fe-based GA are described in Section
17. In conclusion, Section
18 attempts to assess the present knowledge of the structure and physical properties and identify some outstanding problems for future work.
We investigate growing interfaces of topological-defect turbulence in the electroconvection of nematic liquid crystals. The interfaces exhibit self-affine roughening characterized by both spatial and ...temporal scaling laws of the Kardar-Parisi-Zhang theory in 1+1 dimensions. Moreover, we reveal that the distribution and the two-point correlation of the interface fluctuations are universal ones governed by the largest eigenvalue of random matrices. This provides quantitative experimental evidence of the universality prescribing detailed information of scale-invariant fluctuations.
This Letter reports on how the interfaces in the (1+1)-dimensional Kardar-Parisi-Zhang (KPZ) class undergo, in the course of time, a transition from the flat, growing regime to the stationary one. ...Simulations of the polynuclear growth model and experiments on turbulent liquid crystal reveal universal functions of the KPZ class governing this transition, which connect the distribution and correlation functions for the growing and stationary regimes. This in particular shows how interfaces realized in experiments and simulations actually approach the stationary regime, which is never attained unless a stationary interface is artificially given as an initial condition.
Topological defects—locations of local mismatch of order—are a universal concept playing important roles in diverse systems studied in physics and beyond, including the universe, various condensed ...matter systems, and recently, even life phenomena. Among these, liquid crystal has been a platform for studying topological defects via visualization, yet it has been a challenge to resolve three-dimensional structures of dynamically evolving singular topological defects. Here, we report a direct confocal observation of nematic liquid crystalline defect lines, called disclinations, relaxing from an electrically driven turbulent state. We focus in particular on reconnections, characteristic of such line defects. We find a scaling law for in-plane reconnection events, by which the distance between reconnecting disclinations decreases by the square root of time to the reconnection. Moreover, we show that apparently asymmetric dynamics of reconnecting disclinations is actually symmetric in a comoving frame, in marked contrast to the two-dimensional counterpart whose asymmetry is established. We argue, with experimental supports, that this is because of energetically favorable symmetric twist configurations that disclinations take spontaneously, thanks to the topology that allows for rotation of the winding axis. Our work illustrates a general mechanism of such spontaneous symmetry restoring that may apply beyond liquid crystal, which can take place if topologically distinct asymmetric defects in lower dimensions become homeomorphic in higher dimensions and if the symmetric intermediate is energetically favorable.
The forming ability of amorphous and glassy alloys has been assessed with mixing enthalpy (Δ
H
mix) of a liquid phase based on Miedema’s scheme. The Δ
H
mix’s were calculated as a function of ...composition in an alloy for possible 2628 binary systems from 73 elements, and were approximated with interaction parameter
Ω in a sub-regular solution model with coefficients
Ω
i (
i = 0 to 3) for a cubic function of composition. The results revealed that 2627 systems were fitted by
Ω′s within errors denoted by statistical adjusted R-square (
R
2) ≥ 0.999, which includes
R
2 = 1 for 2409 systems. The values of
Ω
i for 1378 systems from 53 elements were selected and tabulated for assessing the forming ability of amorphous and glassy alloys. The analysis revealed that P and C in Fe–P and Fe–C binary alloys and simultaneous additions of Ni and Cu in La-, Zr- and Pd-based bulk metallic glasses exhibit a marked and peculiar composition dependence of Δ
H
mix. In a framework of Miedema’s scheme, the most accurate values of Δ
H
mix for a liquid phase have been provided as a function of composition in an alloy system, which makes it possible to consider the forming ability of amorphous and glassy alloys deeply.
Memory and Universality in Interface Growth De Nardis, Jacopo; Le Doussal, Pierre; Takeuchi, Kazumasa A
Physical review letters,
2017-Mar-24, Letnik:
118, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Recently, very robust universal properties have been shown to arise in one-dimensional growth processes with local stochastic rules, leading to the Kardar-Parisi-Zhang (KPZ) universality class. Yet ...it has remained essentially unknown how fluctuations in these systems correlate at different times. Here, we derive quantitative predictions for the universal form of the two-time aging dynamics of growing interfaces and we show from first principles the breaking of ergodicity that the KPZ time evolution exhibits. We provide corroborating experimental observations on a turbulent liquid crystal system, as well as a numerical simulation of the Eden model, and we demonstrate the universality of our predictions. These results may give insight into memory effects in a broader class of far-from-equilibrium systems.
The Kardar–Parisi–Zhang (KPZ) universality class describes a broad range of non-equilibrium fluctuations, including those of growing interfaces, directed polymers and particle transport, to name but ...a few. Since the year 2000, our understanding of the one-dimensional KPZ class has been completely renewed by mathematical physics approaches based on exact solutions. Mathematical physics has played a central role since then, leading to a myriad of new developments, but their implications are clearly not limited to mathematics — as a matter of fact, it can also be studied experimentally. The aim of these lecture notes is to provide an introduction to the field that is accessible to non-specialists, reviewing basic properties of the KPZ class and highlighting main physical outcomes of mathematical developments since the year 2000. It is written in a brief and self-contained manner, with emphasis put on physical intuitions and implications, while only a small (and mostly not the latest) fraction of mathematical developments could be covered. Liquid-crystal experiments by the author and coworkers are also reviewed.
•A review on recent developments on KPZ, intended for non-specialists, is given.•Physical implications of theoretical results are stressed.•Connections to directed polymer, a quantum many-body system, etc. are explained.•Experimental study using liquid-crystal turbulence is also explained.
Stochastic motion of a point - known as Brownian motion - has many successful applications in science, thanks to its scale invariance and consequent universal features such as Gaussian fluctuations. ...In contrast, the stochastic motion of a line, though it is also scale-invariant and arises in nature as various types of interface growth, is far less understood. The two major missing ingredients are: an experiment that allows a quantitative comparison with theory and an analytic solution of the Kardar-Parisi-Zhang (KPZ) equation, a prototypical equation for describing growing interfaces. Here we solve both problems, showing unprecedented universality beyond the scaling laws. We investigate growing interfaces of liquid-crystal turbulence and find not only universal scaling, but universal distributions of interface positions. They obey the largest-eigenvalue distributions of random matrices and depend on whether the interface is curved or flat, albeit universal in each case. Our exact solution of the KPZ equation provides theoretical explanations.
We provide numerical evidence that a finite-dimensional inertial manifold on which the dynamics of a chaotic dissipative dynamical system lives can be constructed solely from the knowledge of a set ...of unstable periodic orbits. In particular, we determine the dimension of the inertial manifold for the Kuramoto-Sivashinsky system and find it to be equal to the "physical dimension" computed previously via the hyperbolicity properties of covariant Lyapunov vectors.
Upgrade of the KamLAND-Zen mini-balloon and future prospects Ozaki, H.; Takeuchi, A.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958, Številka:
C
Journal Article
Recenzirano
Odprti dostop
KamLAND-Zen is neutrinoless double beta (0νββ) decay search experiment with Xe-loaded liquid scintillator (XeLS) containing about 91% enriched 136Xe. The mini-balloon is a container for holding XeLS ...at the center of the KamLAND detector without impairing the extremely low radiation environment. We have installed a new mini-balloon with a thickness of 25μm and a radius of 1.92 m, which was made in a class 1 clean room and is almost twice the volume of the KamLAND-Zen 400 mini-balloon. We installed about 745 kg of Xe gas in the XeLS and started the 0νββ decay search in January 2019. In this paper, novel hardware developments to collect data without loss just after a large light yield event, such as a cosmic ray muon spallation are also introduced in preparation for the KamLAND2-Zen which is a future upgrade of the KamLAND-Zen.
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