Design and synthesis of multigrain nanocrystals via geometric misfit strain

Oh, Man Hwan; Cho, Min Gee; Chung, Dong Young; Park, In-Chul; Kwon, Youngwook Paul; Ophus, Colin; Kim, Dokyoon; Kim, Min; Jeong, Beomgyun; Gu, X. Wendy; Jo, Jinwoung; Yoo, Ji Mun; Hong, Jaehyun; McMains, Sara; Kang, Kisuk; Sung, Yung‐Eun; Alivisatos, A. Paul; Hyeon, Taeghwan

doi:10.1038/s41586-019-1899-3

Cited by 75 publications

(69 citation statements)

References 30 publications

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“…[ 7,38,40 ] Furthermore, polycrystalline nanofibers with ultrafine grains could tolerate severe deformation owing to the enhanced strength and super plasticity caused by grain‐boundary sliding following the Hall–Petch effect. [ 38,41 ] In contrast, for pure TiO 2 nanofiber, the excessive crystallite growth during calcination process may have either produced surficial defects or less slip system in the fiber which results a catastrophic failure when subjected to external force or load, the stress would condense on these defect areas as macro cracks propagate through the whole fiber. [ 7,39a ] To better illustrate the effects of grain size on the generation, distribution and release of hydrostatic stress, the finite element method is used, as shown in Figure 6c–h.…”

Section: Resultsmentioning

confidence: 99%

Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y³⁺‐Doped TiO₂ Nanofibrous Membranes with Enhanced Flexibility

Joshi

Chen

et al. 2020

Adv Funct Materials

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Free-standing flexible TiO 2 nanofibrous membranes (NFMs) are highly desired for the construction of high-performance wearable electronic devices. Nevertheless, tremendous challenges still exist due to the fragile characteristics of the polycrystalline TiO 2 nanofibers. Here, ultra-flexible TiO 2 NFMs with robust fatigue strength and photoelectric properties are achieved via a simple element doping approach and the electrospinning technique. The 2 mol% Y 3+-doped NFM-based photodetector exhibits excellent UV detecting performance at 3 V under 350 nm illumination, that is, responsivity of 4.5 A W −1 , detectivity of 1.6 × 10 11 Jones, and photocurrent of ≈1.6 µA. By effectively tuning the distribution and bonding state of Y 3+ ions, the NFM shows significantly enhanced flexibility, where its original photocurrent is successfully maintained in various bending states (angle, radius, spiral state). Importantly, the resultant Y 3+-doped TiO 2 NFM maintains ≈60% of its original photocurrent after bending at ≈145° for more than 20 000 times. A plausible prototype accounts for the effective bending deformation mechanism is proposed on the basis of the systematic analyses of the microstructural characteristics and the stress distribution achieved by using the finite element method. Finally, a wearable UV monitoring system that outputs real-time photocurrent signals with different motion combinations of the remote-controlled robot is demonstrated.

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Section: Resultsmentioning

confidence: 99%

Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y³⁺‐Doped TiO₂ Nanofibrous Membranes with Enhanced Flexibility

Joshi

Chen

et al. 2020

Adv Funct Materials

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“…The situation becomes even more interesting when the 3d ion is non-magnetic (as in Cu [5] or Al [6]), as the starting magnetic ordered state can be tuned following two routes: on the one hand, one can modify the random-bond contribution by using 4 f ions as dopants [7,8]. On the other hand, it has been showed that reducing the alloy size to the nanoscale affects the RKKY interactions among the magnetic moments, owing to both finite size effects [9][10][11] and the microstrain associated with grain boundaries [12][13][14]. These usually result in a combination of both frustration and random-site disorder that usually lead to the onset of a SG phase [15,16].…”

Section: Introductionmentioning

confidence: 99%

Exploring the Different Degrees of Magnetic Disorder in TbxR1−xCu2 Nanoparticle Alloys

et al. 2020

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Recently, potential technological interest has been revealed for the production of magnetocaloric alloys using Rare-Earth intermetallics. In this work, three series of TbxR1−xCu2 (R ≡ Gd, La, Y) alloys have been produced in bulk and nanoparticle sizes via arc melting and high energy ball milling. Rietveld refinements of the X-ray and Neutron diffraction patterns indicate that the crystalline structure in all alloys is consistent with TbCu2 orthorhombic Imma bulk crystalline structure. The analyses of the DC-magnetisation (MDC) and AC-susceptibility (χAC) show that three distinct degrees of disorder have been achieved by the combination of both the Tb3+ replacement (dilution) and the nanoscaling. These disordered states are characterised by transitions which are evident to MDC, χAC and specific heat. There exists an evolution from the most ordered Superantiferromagnetic arrangement of the Tb0.5La0.5Cu2 NPs with Néel temperature, TN∼ 27 K, and freezing temperature, Tf∼ 7 K, to the less ordered weakly interacting Superparamagnetism of the Tb0.1Y0.9Cu2 nanoparticles (TN absent, and TB∼ 3 K). The Super Spin Glass Tb0.5Gd0.5Cu2 nanoparticles (TN absent, and Tf∼ 20 K) are considered an intermediate disposition in between those two extremes, according to their enhanced random-bond contribution to frustration.

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“…As there was insufficient energy for the system to reach the equilibrium state at a low temperature, supersaturation of m-HfO2 grains led to lattice distortion of the (1 1 1) planes and a variety of orientations in Region I. The overall growth process could be considered an extension of the Stranski-Krastanov (SK) growth mode [43] for a two-dimensional (2D) thin film to a finite 3D case.…”

Section: Methodsmentioning

confidence: 99%

High-Throughput Growth of HfO2 Films Using Temperature-gradient Laser Chemical Vapor Deposition

Liu

WANG

et al. 2021

Preprint

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The use of hafnia (HfO2) has facilitated recent advances in combining uprated dielectric layers (UDLs) and environmental barriers (EBs) in supercomputers. However, an extremely low deposition rate limits further development and fabrication efficiency of HfO2 films. In this study, high-throughput growth of HfO2 films was realized via laser chemical vapor deposition using a laser spot with a gradient temperature distribution. In HfO2 films fabricated by a single growth process, four regions with different morphologies could be discerned for deposition temperatures increasing from 1300 K to 1600 K: leaf-like, pyramid-like, bromeliad-like and pinecone-like. Two growth modes were observed for Regions I and II: Stranski-Krastanov and Volmer-Weber. Regions III and IV contained coexisting monoclinic and tetragonal HfO2 grains with an in-plane boundary for m-HfO2 (-110) {111}//t-HfO2 (1-11) {111}. The maximum deposition rate reached 362 μm/h, which was 102 - 104 times higher than that obtained using existing deposition methods.

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Design and synthesis of multigrain nanocrystals via geometric misfit strain

Cited by 75 publications

References 30 publications

Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y³⁺‐Doped TiO₂ Nanofibrous Membranes with Enhanced Flexibility

Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y³⁺‐Doped TiO₂ Nanofibrous Membranes with Enhanced Flexibility

Exploring the Different Degrees of Magnetic Disorder in TbxR1−xCu2 Nanoparticle Alloys

High-Throughput Growth of HfO2 Films Using Temperature-gradient Laser Chemical Vapor Deposition

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Design and synthesis of multigrain nanocrystals via geometric misfit strain

Cited by 75 publications

References 30 publications

Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y3+‐Doped TiO2 Nanofibrous Membranes with Enhanced Flexibility

Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y3+‐Doped TiO2 Nanofibrous Membranes with Enhanced Flexibility

Exploring the Different Degrees of Magnetic Disorder in TbxR1−xCu2 Nanoparticle Alloys

High-Throughput Growth of HfO2 Films Using Temperature-gradient Laser Chemical Vapor Deposition

Contact Info

Product

Resources

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Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y³⁺‐Doped TiO₂ Nanofibrous Membranes with Enhanced Flexibility

Mechanically Compatible UV Photodetectors Based on Electrospun Free‐Standing Y³⁺‐Doped TiO₂ Nanofibrous Membranes with Enhanced Flexibility