Structure and dynamics of liquid<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Ni</mml:mtext></mml:mrow><mml:mrow><mml:mn>36</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Zr</mml:mtext></mml:mrow><mml:mrow><mml:mn>64</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>studied by neutron scattering

Holland‐Moritz, D.; Stüber, S.; Hartmann, H.; Unruh, Tobias; Hansen, Thomas C.; Meyer, Andreas

doi:10.1103/physrevb.79.064204

Cited by 93 publications

(45 citation statements)

References 39 publications

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“…Previous studies of Zr-Pt glasses support this, showing that the devitrification pathway changes with Zr concentration, going from glass ⇒ Zr 5 Pt 3 at high Pt concentration to glass ⇒ i-phase ⇒ Zr 5 Pt 3 with increasing Zr 53 and suggesting that icosahedral clusters are the source of the MRO observed. However, the recent observation of a pre-peak in a Zr-Ni liquid 23 from neutron scattering data, which is reported not to have dominate icosahedral short-range order, suggests that icosahedral order isn't always the source of MRO. Instead, a pre-peak is a manifestation of chemical and topological ordering originating from the most common polyhedral cluster in each system-icosahedral or otherwise.…”

Section: Figure 5 Near Herementioning

confidence: 95%

“…Pre-peaks, indicating some degree of medium-range order (MRO), have been observed previously in experimental [15][16][17][18][19] and theoretical 18,20,21 studies of metallic glasses and liquids. However, reports of MRO in metal-metal liquids are rare, 22,23 found primarily in metal-metalloid binary 24,25 and Al-based binary and ternary 17,26,27 alloys. In this letter, we present the results from in-situ high-energy synchrotron X-ray diffraction studies of equilibrium and supercooled Zr 80 Pt 20 liquids (eutectic composition) using the Beamline Electrostatic Levitation (BESL) 28 technique.…”

Section: Introductionmentioning

confidence: 99%

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Short- and medium-range order in Zr80Pt20liquids

Mauro¹,

Wessels

Bendert³

et al. 2011

Phys. Rev. B

100

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The atomic structures in equilibrium and supercooled liquids of Zr 80 Pt 20 were determined as a function of temperature by in-situ high-energy synchrotron diffraction studies of the levitated liquids (containerless processing) using the beamline electrostatic levitation (BESL) technique. The presence of a pronounced pre-peak at q ~ 1.7 Å -1 in the static structure factor indicates medium range order (MRO) in the liquid. The position and intensity of the pre-peak remain constant with cooling, indicating that the MRO is already present in the liquid above its melting temperature. An analysis of the liquid atomic structures obtained using the Reverse Monte Carlo (RMC) method utilizing both the structure factor, S(q), from x-ray diffraction experiments and the partial pair-correlation functions from ab initio molecular dynamics (MD) simulations show that the pre-peak arises from a Pt-Pt correlation that can be indentified with icosahedral short-range order around the Pt atoms. The local atomic ordering is dominated by icosahedral-like structures, raising the nucleation barrier between the liquid and these phases, thus assisting glass formation.

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Section: Figure 5 Near Herementioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Short- and medium-range order in Zr80Pt20liquids

Mauro¹,

Wessels

Bendert³

et al. 2011

Phys. Rev. B

100

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“…For liquid Al 80 Ni 20 a value of E A (Al-Ni) = 0.36 eV is reported [7]. The determination of partial structure factors of molten Zr 64 Ni 36 by elastic neutron scattering by isotopic substitution [8,9] indicates a short-range order different from the icosahedral short-range order observed for a large variety of metallic melts [10]. The short-range order in liquid Zr 64 Ni 36 is characterized by a large local density of packing as indicated by high nearest neighbor coordination number of Z ≈ 13.9.…”

Section: Introductionmentioning

confidence: 99%

Ni self-diffusion in Zr-Ni(-Al) melts

Holland‐Moritz¹,

Stüber²,

Hartmann³

et al. 2009

J. Phys.: Conf. Ser.

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Abstract. We report on investigations on the atomic dynamics in melts of different binary ZrNi alloys and of the ternary glass-forming Zr 60 Ni 25 Al 15 alloy. The liquids are containerlessly processed in an electromagnetic levitator that is combined with quasielastic neutron scattering at the time of flight spectrometer TOFTOF of the FRM II. Ni self-diffusion coefficients are determined that exhibit an Arrhenius-type temperature dependence with comparatively large activation energies ranging between 0.64 and 0.90 eV. Although glass forming abilities and melting temperatures for these alloys exhibit large differences, the absolute values of the selfdiffusion coefficients are similar at same temperature. IntroductionAmong numerous multi-component alloys forming (bulk) metallic glasses [1], one important class of alloys is based on the binary Zr-Ni system. The solidification behaviour of melts and consequently the glass formation process is strongly affected by the the atomic dynamics in the liquid. While for glassforming Pd-(Ni-Cu-)P melts the viscosity is coupled with the diffusivity by the Stokes-Einstein relation above the critical temperature T c of mode-coupling theory [2], for Zr-Ti-Cu-Ni-Be melts viscosity and diffusivity are decoupled above T c and the liquidus temperature T L [3]. Moreover these liquids exhibit considerably smaller values of the Ni self-diffusivity as Pd-(Ni-Cu-)P alloys at similar temperatures. In this work we present investigations on the Ni self-diffusion in melts of different binary Zr-Ni alloys and of the ternary glass forming alloy Zr 60 Ni 25 Al 15 by quasielastic neutron scattering. In order to avoid reactions of the Zr-based melts with crucible materaials and in order to cover a large temperature range including the metastable regime of undercooled liquids at temperature below the melting temperature, the samples are containerlessly processed by application of the electromagnetic levitation technique.

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“…electromagnetic levitation. In [30] [32]; these three alloys show very similar packing fraction and the difference in the measured diffusion coefficients is only a slight one. These findings are somewhat unusual with respect to the fact that liquidus temperature and the capability to undercool these systems strongly depend on the composition.…”

Section: Molten Metalsmentioning

confidence: 78%

“…Note that Eqs. 25, 27 and 29 yield in the small Q limit the generally valid Q 2 -law (long-range diffusion) (30) with the diffusion coefficient D = )r 2 * 6τ . In the large Q limit all models yield -.…”

Section: Jump Diffusionmentioning

confidence: 96%

Introduction to Quasielastic Neutron Scattering

Embs

Jurányi²,

Hempelmann³

2010

Zeitschrift Für Physikalische Chemie

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This tutorial introduction has been written for people who are not specialized in neutron scattering or in other scattering methods but who are interested and would like to get an impression and learn about the method of Quasielastic Neutron Scattering (QENS). The theoretical (scattering process) as well as the experimental basics (neutron sources, neutron scattering instruments, experimental periphery) are explained in a generally understandable way, with only the most essential formulas. QENS addresses the stochastic dynamics in condensed matter, and it is pointed out for which problems and for which systems in condensed matter research QENS is a powerful method. Thus sufficient information is provided to enable non-experts to think about their own QENS experiment and to understand related literature in this area of research.

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Structure and dynamics of liquidNi36Zr64studied by neutron scattering

Cited by 93 publications

References 39 publications

Short- and medium-range order in Zr80Pt20liquids

Short- and medium-range order in Zr80Pt20liquids

Ni self-diffusion in Zr-Ni(-Al) melts

Introduction to Quasielastic Neutron Scattering

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