Crystal Growth & Design最新文献

{"title":"Phase Transition in the Jumping Crystal l-Pyroglutamic Acid: Insights from Dynamic Quantum Crystallography and Spectroscopy","authors":"Anna A. Hoser,&nbsp;Toms Rekis,&nbsp;Helena Butkiewicz,&nbsp;Ka̅rlis Be̅rziņš,&nbsp;Anders S. Larsen,&nbsp;Alexei Bosak,&nbsp;Ben J. Boyd and Anders Ø. Madsen*,&nbsp;","doi":"10.1021/acs.cgd.4c0133510.1021/acs.cgd.4c01335","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01335https://doi.org/10.1021/acs.cgd.4c01335","url":null,"abstract":"<p >Crystals of <span>l</span>-pyroglutamic acid exhibit a thermosalient phenomenon. During nondestructive, reversible phase transitions, the crystals can jump vertically by several centimeters. Such phase transitions have been described as martensitic; displacive, diffusionless transitions. The molecular reorganizations that impart the thermosalient effect have previously been characterized in detail; however, less attention has been given to the dynamics that precede the phase transition. In this study, we analyze the thermal motion and structural organization of the crystals at temperatures close to the phase transition using X-ray diffraction and low-frequency Raman spectroscopy. These analyses are supported by periodic density functional theory (DFT) calculations. The free energies derived from the lattice dynamics models refined against X-ray data provide a qualitative picture of the relative free energies of the involved crystal phases. The low-frequency phonons are analyzed to find possible molecular motion that can drive the phase transitions. The Raman measurements interpreted in light of spectra derived the periodic DFT calculations, as well as the observed diffuse scattering and correlated disorder, imply that a simplistic picture of a clean phase transition from one periodic crystal lattice to another must be abandoned.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"593–602 593–602"},"PeriodicalIF":3.2,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering the Pore Size and Environment of Pillar-Layered Zinc-Azolate-Carboxylate Frameworks for Efficient CH4 Purification and C2H2/CO2 Separation","authors":"Zhao-Di Dou,&nbsp;Hai-Peng Li*,&nbsp;Yutong Chen,&nbsp;Wen-Hua Bai,&nbsp;Yu-Lian Ma,&nbsp;Xiao-Lan Li,&nbsp;Ying-Juan Li,&nbsp;Ning-Juan Xi and Xiangyu Liu*,&nbsp;","doi":"10.1021/acs.cgd.4c0125310.1021/acs.cgd.4c01253","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01253https://doi.org/10.1021/acs.cgd.4c01253","url":null,"abstract":"<p >It is widely believed that engineering the pore size and environment of metal–organic frameworks (MOFs) is an effective method to improve their gas adsorption and separation performance. Herein, the pore size and environment of two pillar-layered zinc-azolate-carboxylate frameworks, {[Me₂NH₂]₂[Zn(H₂O)₆][Zn₈(PzC)₈(IM)₄]}_n (compound <b>1</b>) and {[Me₂NH₂][Zn₂(PzC)₂(ATAZ)]}_n (compound <b>2</b>) (where Me₂NH₂⁺ is the dimethylammonium cation produced by the decomposition of DMF molecules, PzC = 4-pyrazolatecarboxylate, IM = imidazolate, and ATAZ = 5-amino-1H-tetrazolate), were effectively regulated by using different azole ligands. Single-crystal X-ray diffraction data indicated that both compound <b>1</b> and compound <b>2</b> are 3D pillar-layered zinc-azolate-carboxylate frameworks constructed by connecting adjacent 2D grid-like zinc-azolate-carboxylate layers through IM or ATAZ ligands. The angle between the two adjacent PzC ligands in the 2D grid-like zinc-azolate-carboxylate layers of those two compounds is different, leading to large differences in the pore size and shape of those two compounds. Additionally, uncoordinate N atoms and the -NH₂ functional groups in the ATAZ ligand make compound <b>2</b> pores have more abundant Lewis N sites and −NH₂ functional groups. Gas adsorption and separation results indicated that compound <b>2</b> demonstrates preferential adsorption of C2 hydrocarbons and CO₂ gases over CH₄ with superior CO₂–CH₄, C₂H₂–CH₄, C₂H₄–CH₄ C₂H₆–CH₄, and C₂H₂–CO₂ binary mixture breakthrough time of 33, 57, 55, 60, and 17 min g^–1 at 298 K. GCMC simulation is further used to explore the interaction between the MOFs and gas molecules.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"563–571 563–571"},"PeriodicalIF":3.2,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Superconducting Phase UTe2 Single Crystals Grown by the Chemistry Vapor Transport Method","authors":"Ning Li,&nbsp;Zheyin Chen,&nbsp;Tianzhi Li,&nbsp;Chaofan Zhang* and Bin-Bin Zhang*,&nbsp;","doi":"10.1021/acs.cgd.4c0164410.1021/acs.cgd.4c01644","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01644https://doi.org/10.1021/acs.cgd.4c01644","url":null,"abstract":"<p >Recently, a uranium-based compound, UTe₂, has shown remarkable superconducting properties, including an extraordinarily large upper critical field (&gt;65 T) surpassing the Pauli limit, anomalous ¹²⁵Te-NMR Knight shifts, and the presence of chiral edge states. These characteristics place UTe₂ among the few strong candidates for spin-triplet superconductors. However, the underlying mechanism of superconductivity in UTe₂ remains elusive and is highly sensitive to the synthesis conditions, composition, and quality of the UTe₂ single crystals. To address this, we have meticulously grown UTe₂ crystals using the chemical vapor transport method, systematically varying parameters such as the starting material ratio of Te/U and the temperature gradient (Δ<i>T</i>). Our findings reveal that the morphology of the grown UTe₂ crystals transitions from bulk- to flake-like as the Te/U ratio falls below 2. Additionally, the size and quality of the crystals can be modulated by adjusting Δ<i>T</i>. The largest UTe₂ crystal obtained had dimensions of approximately 7 × 8 × 5 cm³ and a weight of 0.6021 g. A phase diagram dependent on the initial Te/U ratio was constructed based on magnetism measurements, showing that the superconducting region lies within the range of 1.6 &lt; Te/U &lt; 2.0, with the highest superconducting transition temperature (<i>T</i>_c) found to be around 1.75 K. Our results indicate that component sensitivities and impurities pose significant challenges in achieving higher <i>T</i>_c in UTe₂.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"833–837 833–837"},"PeriodicalIF":3.2,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143126945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Coherent Grain Boundaries Induced by Local Pseudomirror Symmetry in β-Ga2O3","authors":"Yuchao Yan,&nbsp;Yingying Liu,&nbsp;Ziyi Wang,&nbsp;Da Liu,&nbsp;Xu Gao,&nbsp;Yan Wang,&nbsp;Cheng Li,&nbsp;KeKe Ma,&nbsp;Ning Xia,&nbsp;Zhu Jin*,&nbsp;Tianqi Deng*,&nbsp;Hui Zhang* and Deren Yang,&nbsp;","doi":"10.1021/acs.cgd.4c0150410.1021/acs.cgd.4c01504","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01504https://doi.org/10.1021/acs.cgd.4c01504","url":null,"abstract":"<p >Grain boundaries have an extensive influence on the performance of crystal materials. However, the atomic-scale structures and their relations to local and crystallographic symmetries remain elusive in low-symmetry crystals. Herein, we find that the local pseudomirror-symmetric atomic layer is the common physical origin of a series of highly coherent grain boundaries in the low-symmetry β-Ga₂O₃ crystal. These include the (100) twin boundary and an emerging series of (<i>h</i>-1′0′2)<i>/</i>(<i>h</i>+1′0′2̅) coherent asymmetric grain boundaries (CAGBs). Owing to the local pseudomirror symmetry and the special geometric relation of the β-Ga₂O₃ conventional cell, these CAGBs place 80% of the boundary atoms in pseudocoincident sites, exhibiting high coherence under the coincident-site lattice model. With a combination of density functional theory calculations, Czochralski growth experiment, and atomic-scale characterizations, the structure and stability of the (002)<i>/</i>(202̅)-A CAGB are confirmed, with an interface energy density as low as 0.36 J m^–2. This CAGB is responsible for the spontaneous formation of a twinned defect facet at the surface steps during the epitaxy growth of β-Ga₂O₃, warranting a substrate orientation selection rule for β-Ga₂O₃. Through this study, we provide insights into the grain boundary physics in the low-symmetry β-Ga₂O₃ crystal while emphasizing the importance of the local pseudosymmetries in the low-symmetry crystals.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"713–719 713–719"},"PeriodicalIF":3.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Giant Growth of Crystalline Films of 1,3,5-Tris(N-carbazolyl)benzene (TCB) and 1,3,5-Tris(diphenylamino)benzene (TDAB) on Engineered Shapes of Ionic Liquid in Vacuum","authors":"Artur F. M. Farinha,&nbsp;Gonçalo N. P. Oliveira,&nbsp;João P. Araújo,&nbsp;Luís M. N. B. F. Santos and José C. S. Costa*,&nbsp;","doi":"10.1021/acs.cgd.4c0135510.1021/acs.cgd.4c01355","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01355https://doi.org/10.1021/acs.cgd.4c01355","url":null,"abstract":"<p >This study demonstrates the efficacy of ionic liquid (IL)-assisted vapor deposition in achieving high-quality and distinctive crystal film growth of two organic semiconductors (OSCs): a carbazole derivative (TCB) and a phenylamine derivative (TDAB). ILs with different wetting properties (short-chain [C₂C₁im][NTf₂] and long-chain [C₈C₁im][NTf₂]) and engineered shapes (microdroplets and coalesced film) were utilized as solvents in a vacuum. Through a meticulously designed experimental strategy, encompassing both sequential and simultaneous deposition of the IL and the OSC, this study unveils the pivotal role of ILs in shaping the crystallization behavior of the organic compound. Differential scanning calorimetry, polarized light microscopy, high-resolution scanning electron microscopy, and X-ray diffraction were employed for the films’ thermal, morphological, and structural characterization. Thin films of TDAB exhibit crystallinity and a greater tendency to grow tridimensionally, forming giant pillars. However, the typical vertical growth of TDAB on solid substrates is altered when deposition occurs on surfaces coated with ILs. The IL promotes the lateral growth of nanostructures. The experimental results reveal variations in film morphology and coverage influenced by the cation alkyl chain length of the IL. In contrast to TDAB, TCB films are amorphous when thermally evaporated on solid substrates. Notably, IL-assisted vapor deposition induces the crystallization of TCB. Furthermore, TCB films deposited on coalesced IL films exhibit enhanced crystallinity and homogeneous horizontal growth, representing a significant finding in the context of thin film deposition and semiconductor device fabrication.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"612–623 612–623"},"PeriodicalIF":3.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Situ Ligand Transformation for the Development of Luminescent 3D Metal–Organic Frameworks with Diamond-like Topology","authors":"Antonio A. García-Valdivia,&nbsp;Sara Rojas,&nbsp;Duane Choquesillo-Lazarte,&nbsp;Antonio Rodríguez-Diéguez,&nbsp;José Ángel García,&nbsp;Javier Cepeda* and Pablo Salcedo-Abraira*,&nbsp;","doi":"10.1021/acs.cgd.4c0149610.1021/acs.cgd.4c01496","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01496https://doi.org/10.1021/acs.cgd.4c01496","url":null,"abstract":"<p >Here, the synthesis by a soft solvothermal route of two novel isoreticular compounds based on the in situ generated (by a nucleophilic aromatic substitution) 2-hydroxi-5-(trifluoromethyl)pyrimidine (H₁L) ligand and Zn(II) and Cd(II) as metallic centers (with the general formula [ML₂]_n and labeled as GR-MOF-30 for M = Zn and GR-MOF-31 for M = Cd) is reported, together with their detailed structural and photoluminescent characterization. These metal–organic frameworks are the first examples of coordination compounds based on Zn(II) and Cd(II) constructed with this novel ligand. Structures show remarkable intermolecular interactions, including C–F···π and π···π stacking, which not only stabilize the structure but also improve the luminescent properties of the materials. DFT calculations were employed to unequivocally assign the bands observed in UV–vis solid-state spectroscopy. A photophysical study of the materials revealed that GR-MOF-30 and GR-MOF-31present fluorescence band maxima at 394 and 388 nm, respectively, with phosphorescence band maxima and emission lifetimes of 500 and 48.1 ms for <b>GR-MOF-30</b> and 450 and 69.2 ms for GR-MOF-31. Interestingly, the photoluminescence properties of compound GR-MOF-30 are hardly affected by the change of temperature; meanwhile, GR-MOF-31 shows a transition from a dominating fluorescent emission at room temperature to a phosphorescent emission at 25 K.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"703–712 703–712"},"PeriodicalIF":3.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Color-Tunable Photoluminescence via Site-Selective Occupancy of Bi3+/Eu3+ and Chemical Composition Modulation in Stable K3YSi2O7 toward wLED and Optical Temperature-Sensing Applications","authors":"Chengyu Ni,&nbsp;Kaiting Wu,&nbsp;Chunxuan Chen,&nbsp;Xiaozhou Zheng,&nbsp;Man Xu and Wubin Dai*,&nbsp;","doi":"10.1021/acs.cgd.4c0157010.1021/acs.cgd.4c01570","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01570https://doi.org/10.1021/acs.cgd.4c01570","url":null,"abstract":"<p >The design of a stably efficient and color-tunable photoluminescence (PL) phosphor, depending on the clear relationship between structure/composition and PL properties, remains quite a challenge. Herein, in pursuit of phosphor for white LED (wLED) lighting, chemical modification of the host (K₃YSi₂O₇, KYS) and regulation of the energy transfer of dopants Bi³⁺/Eu³⁺ in multiple lattice sites (K/Y) are in detail investigated and achieved via a facile solid-phase reaction under air condition. Based on both experimentally and theoretically comprehensive analysis of structure (i.e., XRD/Rietveld refinement, density functional theory (DFT) calculations) and steady/transient-state spectroscopy (i.e., PL/PL excitation, decay lifetime), the adjustable and broad PL in the blue/cyan region of Bi³⁺ is originated from both the crystallographic sites of K1/Y2, while Eu³⁺ ions are more inclined to enter the Y2/Y1 sites and emit the characteristic high-purity red PL. Systematic PL tuning from blue/cyan to red is thus realized via efficient ET from Bi to Eu, and the corresponding PL and ET mechanisms are discussed and proposed. Intriguingly, significant enhancements of the PL intensity, quantum yield (QY), and thermal stability of the KYS: Bi/Eu are achieved via chemical composition modulation by artificially adding excessive K⁺ ions to the host to enhance the phase purity/crystallinity. By adopting the phosphor as a “warm” white color convertor, a wLED with high efficiency and color rendering index (CRI, 90.5) and low corrected color temperature (CCT, 4126 K) is constructed via a remote “capping” packaging strategy. Further, in view of the different thermal responses of the multisite occupancy of Bi³⁺, energy-level thermal coupling of Eu³⁺, and dual centers of Bi/Eu in KYS, a multimode and self-referenced thermometer is also designed based on the fluorescence intensity ratio (FIR) technology with high relative sensitivity.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"777–789 777–789"},"PeriodicalIF":3.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multicomponent Crystal Forms of Albendazole for Bioavailability Improvement","authors":"Mayowa A. N. Adegbolagun,&nbsp;Ke Wang,&nbsp;Toshio Yamaguchi,&nbsp;Tomohiko Hamaguchi,&nbsp;Koji Yoshida,&nbsp;Satoshi Kawata,&nbsp;Colin C. Seaton,&nbsp;Azuchi Harano,&nbsp;Jun Han,&nbsp;Zhengping Wang and Mingzhong Li*,&nbsp;","doi":"10.1021/acs.cgd.4c0120810.1021/acs.cgd.4c01208","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01208https://doi.org/10.1021/acs.cgd.4c01208","url":null,"abstract":"<p >In this study, a large-scale screening of multicomponent crystal forms of albendazole (ABZ) was carried out, aiming to improve its solubility and dissolution rate for bioavailability improvement. A computational prescreening tool based on the hydrogen bond energy was employed for initial selection of the coformer candidates to shorten the period and number of the experimental investigations, leading to the discovery of eight ABZ multicomponent solids, e.g., 1:1 albendazole-alpha-ketoglutaric acid (ABZ-AKA), 1:1 albendazole - etidronic acid (ABZ-ETA), 1:1 albendazole - (R)-mandelic acid (ABZ-RMA), albendazole - (S)-mandelic acid (1:1 ABZ-SMA), albendazole - citraconic acid (1:1 ABZ-CTA), 1:1 albendazole - mandelic acid (ABZ-MDA), 1:1 albendazole - cyclamic acid (ABZ-CYA), and albendazole - malonic acid (1:1 ABZ-MLA). Although these solids are salt cocrystal adducts based on the Δp<i>K</i>_a rule, they are all salt forms according to the structure analyses and FTIR results. The dissolution study has shown that the cocrystals of both ABZ-ETA and ABZ-CYA significantly improved the ABZ dissolution performance in comparison with the parent drug of ABZ.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"540–553 540–553"},"PeriodicalIF":3.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High L10-Ordering and Flat Surface Introducing a Two-Step Heating Process with Frank–Van der Merwe Initial Growth Mode at Low Temperature","authors":"Samuel Vergara,&nbsp; and ,&nbsp;Hiroshi Naganuma*,&nbsp;","doi":"10.1021/acs.cgd.4c0154910.1021/acs.cgd.4c01549","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01549https://doi.org/10.1021/acs.cgd.4c01549","url":null,"abstract":"<p >FePd films were epitaxially grown on SrTiO₃ (001) substrates by rf magnetron sputtering. The preferred crystal orientation of FePd was (111)_fcc when the substrate temperature (<i>T</i>_s) was room temperature during film deposition. Above <i>T</i>_s = 150 °C, the main preferred orientation of FePd changed from (111) to (001). Above <i>T</i>_s = 400 °C, the degree of <i>L</i>1₀ ordering (S_L10) of FePd increased monotonically and reached 0.88 at <i>T</i>_s = 600 °C. Below <i>T</i>_s = 350 °C, a flat surface was formed, which might be considered Frank–Van der Merwe’s (FM) mode growth. Above <i>T</i>_s = 400 °C, the surface roughness (<i>R</i>_a) increased and reached <i>R</i>_a of 3.9 nm at <i>T</i>_s = 600 °C. We call this as a ‘<i>one-step heating process</i>’. The high S_L10 and flat surface were not simultaneously obtained by the one-step heating process. We introduced the ’<i>two-step heating method</i>’ to obtain high S_L10 and flat surface simultaneously: the films were grown at low <i>T</i>_s, followed by postannealing at <i>T</i>_a = 600 °C. This two-step heating method realized a high S_L10 of 0.98 (considering the Pd excess composition) and a flat surface (<i>R</i>_a = 0.3 nm) by <i>T</i>_s = 150 °C followed by <i>T</i>_a = 600 °C. By the two-step heating, the S_L10 increased from 0.88 to 0.98, and the flatness improved from 3.9 to 0.3 nm. The flat surface is thought to be due to FM growth mode because FePd film was deposited at low <i>T</i>_s such as 150 °C, and once a flat surface was formed at low <i>T</i>_s, the flat surface was maintained even after <i>T</i>_a = 600 °C. For the reason for the high degree of <i>L</i>1₀ ordering at a flat surface, we consider that the flat surface reducing the atoms on the slope caused by coarse grains result in promoting <i>L</i>1₀ ordering. <i>K</i>_u was 1.04 MJ/m³ at 300 K (1.20 MJ/m³ at 10 K), and the high perpendicular magnetic anisotropy (PMA) resulted in a small temperature dependence of <i>K</i>_u and <i>M</i>_s. It is expected that the PMA can be increased to a theoretical value (2 MJ/m³) by removing the twin-like dislocations observed in the cross-sectional transmission electron microscope images.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"768–776 768–776"},"PeriodicalIF":3.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143127026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizations and Modeling of Grown MQS Nanowires with GaInN/GaN Superlattice Structures","authors":"Jinjian Yan,&nbsp;Soma Inaba,&nbsp;Weifang Lu*,&nbsp;Yang Bao,&nbsp;Yang Sun,&nbsp;Jinchai Li,&nbsp;Motoaki Iwaya,&nbsp;Kai Huang*,&nbsp;Junyong Kang,&nbsp;Tetsuya Takeuchi,&nbsp;Rong Zhang and Satoshi Kamiyama,&nbsp;","doi":"10.1021/acs.cgd.4c0138810.1021/acs.cgd.4c01388","DOIUrl":"https://doi.org/10.1021/acs.cgd.4c01388https://doi.org/10.1021/acs.cgd.4c01388","url":null,"abstract":"<p >The development of the micro-light-emitting diode (Micro-LED) based on GaN nanostructures has brought great prospects for high-quality display applications. In this study, selective-area growth by metal–organic chemical vapor deposition (MOCVD) technology was applied to prepare coaxial GaInN/GaN multi-quantum-shell (MQS) nanowires (NWs) with different crystalline planes. The morphology and emission characterization results demonstrated that the GaInN/GaN superlattices (SLs) effectively reduced the density of point defects in the subsequent grown MQS structures. The NWs containing SLs exhibited larger dimensions and superior emission uniformity on the (101̅1) and (0001)-planes apex region. Moreover, the cathodoluminescence (CL) intensity of NWs with SLs was significantly enhanced, and the time-resolved CL measurements also demonstrated an improvement in crystalline quality. This was mainly attributed to the suppressed migration of point defects to MQS by inserting SLs, thereby improving the crystalline quality of MQSs. We elucidated the mechanism that inhibits the migration of point defects in epitaxial SLs on different crystalline planes through first-principles calculations. Specifically, the calculation indicated that the nitrogen vacancies were preferably localized near In atoms, leading to the suppressed migration of point defects in SLs toward the subsequent growth layer. The variations in growth rates observed among distinct crystalline planes in NWs can be explained by the total energy calculations of atomic adsorption on different crystalline planes and the mechanism of hydrogen passivation. Through the elucidation of the growth mechanism, our study provides valuable insights for optimizing epitaxial growth processes in the development of advanced optoelectronic devices.</p>","PeriodicalId":34,"journal":{"name":"Crystal Growth & Design","volume":"25 3","pages":"639–649 639–649"},"PeriodicalIF":3.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143126844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}