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Goossens E, Aalling-Frederiksen O, Tack P, Van den Eynden D, Walsh-Korb Z, Jensen KMØ, De Buysser K, De Roo J. From Gel to Crystal: Mechanism of HfO 2 and ZrO 2 Nanocrystal Synthesis in Benzyl Alcohol. J Am Chem Soc 2024; 146:10723-10734. [PMID: 38588404 PMCID: PMC11027147 DOI: 10.1021/jacs.4c00678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/08/2024] [Accepted: 03/25/2024] [Indexed: 04/10/2024]
Abstract
Nonaqueous sol-gel syntheses have been used to make many types of metal oxide nanocrystals. According to the current paradigm, nonaqueous syntheses have slow kinetics, thus favoring the thermodynamic (crystalline) product. Here we investigate the synthesis of hafnium (and zirconium) oxide nanocrystals from the metal chloride in benzyl alcohol. We follow the transition from precursor to nanocrystal through a combination of rheology, EXAFS, NMR, TEM, and X-ray total scattering (PDF analysis). Upon dissolving the metal chloride precursor, the exchange of chloride ligands for benzylalkoxide liberates HCl. The latter catalyzes the etherification of benzyl alcohol, eliminating water. During the temperature ramp to the reaction temperature (220 °C), sufficient water is produced to turn the reaction mixture into a macroscopic gel. Rheological analysis shows a network consisting of strong interactions with temperature-dependent restructuring. After a few minutes at the reaction temperature, crystalline particles emerge from the gel, and nucleation and growth are complete after 30 min. In contrast, 4 h are required to obtain the highest isolated yield, which we attribute to the slow in situ formation of water (the extraction solvent). We used our mechanistic insights to optimize the synthesis, achieving high isolated yields with a reduced reaction time. Our results oppose the idea that nonaqueous sol-gel syntheses necessarily form crystalline products in one step, without a transient, amorphous gel state.
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Affiliation(s)
- Eline Goossens
- Department
of Chemistry, Ghent University, 9000 Ghent, Belgium
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
| | | | - Pieter Tack
- Department
of Chemistry, Ghent University, 9000 Ghent, Belgium
| | - Dietger Van den Eynden
- Department
of Chemistry, Ghent University, 9000 Ghent, Belgium
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
| | - Zarah Walsh-Korb
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
| | | | | | - Jonathan De Roo
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
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2
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Van den Eynden D, Pokratath R, De Roo J. Nonaqueous Chemistry of Group 4 Oxo Clusters and Colloidal Metal Oxide Nanocrystals. Chem Rev 2022; 122:10538-10572. [PMID: 35467844 DOI: 10.1021/acs.chemrev.1c01008] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We review the nonaqueous precursor chemistry of the group 4 metals to gain insight into the formation of their oxo clusters and colloidal oxide nanocrystals. We first describe the properties and structures of titanium, zirconium, and hafnium oxides. Second, we introduce the different precursors that are used in the synthesis of oxo clusters and oxide nanocrystals. We review the structures of group 4 metal halides and alkoxides and their reactivity toward alcohols, carboxylic acids, etc. Third, we discuss fully condensed and atomically precise metal oxo clusters that could serve as nanocrystal models. By comparing the reaction conditions and reagents, we provide insight into the relationship between the cluster structure and the nature of the carboxylate capping ligands. We also briefly discuss the use of oxo clusters. Finally, we review the nonaqueous synthesis of group 4 oxide nanocrystals, including both surfactant-free and surfactant-assisted syntheses. We focus on their precursor chemistry and surface chemistry. By putting these results together, we connect the dots and obtain more insight into the fascinating chemistry of the group 4 metals. At the same time, we also identify gaps in our knowledge and thus areas for future research.
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Affiliation(s)
- Dietger Van den Eynden
- Department of Chemistry, University of Basel, Mattenstrasse 24, BPR 1096, Basel 4058, Switzerland
| | - Rohan Pokratath
- Department of Chemistry, University of Basel, Mattenstrasse 24, BPR 1096, Basel 4058, Switzerland
| | - Jonathan De Roo
- Department of Chemistry, University of Basel, Mattenstrasse 24, BPR 1096, Basel 4058, Switzerland
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3
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Li P, Zhang Y, Guo Y, Jiang L, Zhang Z, Xu C. Resistance Switching Behavior of a Perhydropolysilazane-Derived SiO x-Based Memristor. J Phys Chem Lett 2021; 12:10728-10734. [PMID: 34710322 DOI: 10.1021/acs.jpclett.1c03031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
SiOx is an important dielectric material layer for resistive switching memory due to its compatibility with complementary metal-oxide semiconductor (CMOS) technology. Here we propose a solution process for a SiOx dielectric layer based on perhydropolysilazane (PHPS). A series of SiOx layers with different compositions are prepared by controlling the conversion process from PHPS, then the resistance switching behaviors of typical Ag/SiOx/Au memristors are analyzed. The effect of oxygen vacancies and Si-OH groups on the formation and rupture of Ag conducting filaments (CFs) in the SiOx layer was thoroughly investigated. Ultimately, we achieved a high-performance memristor with a coefficient of variation (σ/μ) as low as 0.16 ± 0.08 and an on/off ratio as high as 106, which can rival the performance of the SiOx memristors based on the high-vacuum and high-cost vapor deposition methods. These findings demonstrate the high promise of the PHPS-derived SiOx dielectric layer in the field of memristors.
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Affiliation(s)
- Pengfei Li
- Key Laboratory of Science and Technology on High-Tech Polymer Materials, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Yulin Zhang
- Key Laboratory of Science and Technology on High-Tech Polymer Materials, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100149, People's Republic of China
| | - Yunlong Guo
- Key Laboratory of Science and Technology on High-Tech Polymer Materials, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Lang Jiang
- Key Laboratory of Science and Technology on High-Tech Polymer Materials, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Zongbo Zhang
- Key Laboratory of Science and Technology on High-Tech Polymer Materials, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Caihong Xu
- Key Laboratory of Science and Technology on High-Tech Polymer Materials, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100149, People's Republic of China
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4
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Zhou Z, López-Domínguez P, Abdullah M, Barber DM, Meng X, Park J, Van Driessche I, Schiffman JD, Crosby AJ, Kittilstved KR, Nonnenmann SS. Memristive Behavior of Mixed Oxide Nanocrystal Assemblies. ACS APPLIED MATERIALS & INTERFACES 2021; 13:21635-21644. [PMID: 33938727 DOI: 10.1021/acsami.1c03722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Recent advances in memristive nanocrystal assemblies leverage controllable colloidal chemistry to induce a broad range of defect-mediated electrochemical reactions, switching phenomena, and modulate active parameters. The sample geometry of virtually all resistive switching studies involves thin film layers comprising monomodal diameter nanocrystals. Here we explore the evolution of bipolar and threshold resistive switching across highly ordered, solution-processed nanoribbon assemblies and mixtures comprising BaZrO3 (BZO) and SrZrO3 (SZO) nanocrystals. The effects of nanocrystal size, packing density, and A-site substitution on operating voltage (VSET and VTH) and switching mechanism were studied through a systematic comparison of nanoribbon heterogeneity (i.e., BZO-BZO vs BZO-SZO) and monomodal vs bimodal size distributions (i.e., small-small and small-large). Analysis of the current-voltage response confirms that tip-induced, trap-mediated space-charge-limited current and trap-assisted tunneling processes drive the low- and high-resistance states, respectively. Our results demonstrate that both smaller nanocrystals and heavier alkaline earth substitution decrease the onset voltage and improve stability and state retention of monomodal assemblies and bimodal nanocrystal mixtures, thus providing a base correlation that informs fabrication of solution-processed, memristive nanocrystal assemblies.
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Affiliation(s)
- Zimu Zhou
- Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | | | - Muhammad Abdullah
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Dylan M Barber
- Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Xiangxi Meng
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Jieun Park
- Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | | | - Jessica D Schiffman
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Alfred J Crosby
- Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Kevin R Kittilstved
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Stephen S Nonnenmann
- Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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5
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Analog Memristive Characteristics of Square Shaped Lanthanum Oxide Nanoplates Layered Device. NANOMATERIALS 2021; 11:nano11020441. [PMID: 33572253 PMCID: PMC7915431 DOI: 10.3390/nano11020441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/06/2021] [Accepted: 02/07/2021] [Indexed: 12/04/2022]
Abstract
Square-shaped or rectangular nanoparticles (NPs) of lanthanum oxide (LaOx) were synthesized and layered by convective self-assembly to demonstrate an analog memristive device in this study. Along with non-volatile analog memory effect, selection diode property could be co-existent without any implementation of heterogeneous multiple stacks with ~1 μm thick LaOx NPs layer. Current–voltage (I–V) behavior of the LaOx NPs resistive switching (RS) device has shown an evolved current level with memristive behavior and additional rectification functionality with threshold voltage. The concurrent memristor and diode type selector characteristics were examined with electrical stimuli or spikes for the duration of 10–50 ms pulse biases. The pulsed spike increased current levels at a read voltage of +0.2 V sequentially along with ±7 V biases, which have emulated neuromorphic operation of long-term potentiation (LTP). This study can open a new application of rare-earth LaOx NPs as a component of neuromorphic synaptic device.
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Carlos E, Branquinho R, Martins R, Kiazadeh A, Fortunato E. Recent Progress in Solution-Based Metal Oxide Resistive Switching Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2004328. [PMID: 33314334 DOI: 10.1002/adma.202004328] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 09/08/2020] [Indexed: 06/12/2023]
Abstract
Metal oxide resistive switching memories have been a crucial component for the requirements of the Internet of Things, which demands ultra-low power and high-density devices with new computing principles, exploiting low cost green products and technologies. Most of the reported resistive switching devices use conventional methods (physical and chemical vapor deposition), which are quite expensive due to their up-scale production. Solution-processing methods have been improved, being now a reliable technology that offers many advantages for resistive random-access memory (RRAM) such as high versatility, large area uniformity, transparency, low-cost and a simple fabrication of two-terminal structures. Solution-based metal oxide RRAM devices are emergent and promising non-volatile memories for future electronics. In this review, a brief history of non-volatile memories is highlighted as well as the present status of solution-based metal oxide resistive random-access memory (S-RRAM). Then, a focus on describing the solution synthesis parameters of S-RRAMs which induce a massive influence in the overall performance of these devices is discussed. Next, a precise analysis is performed on the metal oxide thin film and electrode interface and the recent advances on S-RRAM that will allow their large-area manufacturing. Finally, the figures of merit and the main challenges in S-RRAMs are discussed and future trends are proposed.
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Affiliation(s)
- Emanuel Carlos
- CENIMAT/i3N Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia (FCT), Universidade NOVA de Lisboa (UNL), and CEMOP/UNINOVA, Caparica, 2829-516, Portugal
| | - Rita Branquinho
- CENIMAT/i3N Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia (FCT), Universidade NOVA de Lisboa (UNL), and CEMOP/UNINOVA, Caparica, 2829-516, Portugal
| | - Rodrigo Martins
- CENIMAT/i3N Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia (FCT), Universidade NOVA de Lisboa (UNL), and CEMOP/UNINOVA, Caparica, 2829-516, Portugal
| | - Asal Kiazadeh
- CENIMAT/i3N Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia (FCT), Universidade NOVA de Lisboa (UNL), and CEMOP/UNINOVA, Caparica, 2829-516, Portugal
| | - Elvira Fortunato
- CENIMAT/i3N Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia (FCT), Universidade NOVA de Lisboa (UNL), and CEMOP/UNINOVA, Caparica, 2829-516, Portugal
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7
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Resistive switching characteristics of ZnO nanoparticles layer-by-layer assembly based on cortisol and its antibody immune binding. J IND ENG CHEM 2019. [DOI: 10.1016/j.jiec.2019.06.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Choudhary S, Crosby AJ. Controlled evaporative self‐assembly of polymer nanoribbons using oscillating capillary bridges. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/polb.24730] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Satyan Choudhary
- Department of Polymer Science and Engineering University of Massachusetts Amherst, Silvio O. Conte National Center for Polymer Research 120 Governors Drive, Amherst Massachusetts, 01003
| | - Alfred J. Crosby
- Department of Polymer Science and Engineering University of Massachusetts Amherst, Silvio O. Conte National Center for Polymer Research 120 Governors Drive, Amherst Massachusetts, 01003
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