High thermal robustness of molecularly thin perovskite nanosheets and implications for superior dielectric properties

Bao Wen Li, Minoru Osada, Yasuo Ebina, Kosho Akatsuka, Katsutoshi Fukuda, Takayoshi Sasaki

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

A systematic study has been conducted to examine the thermal stability of layer-by-layer assembled films of perovskite-type nanosheets, (Ca 2Nb3O10 -)n (n = 1-10), which exhibit superior dielectric and insulating properties. In-plane and out-of-plane X-ray diffraction data as well as observations by atomic force microscopy and transmission electron microscopy indicated the high thermal robustness of the nanosheet films. In a monolayer film with an extremely small thickness of ∼2 nm, the nanosheet was stable up to 800°C, the temperature above which segregation into CaNb2O6 and Ca2Nb2O7 began. The critical temperature moderately decreased as the film thickness, or the number of nanosheet layers, increased, and reached 700°C for seven- and 10-layer films, which is comparable to the phase transformation temperature for a bulk phase of the protonic layered oxide of HCa2Nb3O10·1. 5H2O as a precursor of the nanosheet. This thermal stabilization of perovskite-type nanosheets should be associated with restricted nucleation and crystal growth peculiar to such ultrathin 2D bound systems. The stable high-k dielectric response (εr = 210) and highly insulating nature (J < 10-7 A cm-2) remained substantially unchanged even after the nanosheet film was annealed up to 600°C. This study demonstrates the high thermal stability of 2D perovskite-type niobate nanosheets in terms of structure and dielectric properties, which suggests promising potential for future high-k devices operable over a wide temperature range.

Original languageEnglish
Pages (from-to)5449-5461
Number of pages13
JournalACS Nano
Volume8
Issue number6
DOIs
Publication statusPublished - 2014 Jun 24
Externally publishedYes

Fingerprint

Nanosheets
Dielectric properties
Perovskite
dielectric properties
thermal stability
niobates
Thermodynamic stability
phase transformations
temperature
crystal growth
critical temperature
film thickness
Temperature
stabilization
Hot Temperature
perovskite
atomic force microscopy
nucleation
Crystallization
transmission electron microscopy

Keywords

  • layer-by-layer assembly
  • nanodielectrics
  • perovskite-type nanosheets
  • thermal stability

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

Cite this

High thermal robustness of molecularly thin perovskite nanosheets and implications for superior dielectric properties. / Li, Bao Wen; Osada, Minoru; Ebina, Yasuo; Akatsuka, Kosho; Fukuda, Katsutoshi; Sasaki, Takayoshi.

In: ACS Nano, Vol. 8, No. 6, 24.06.2014, p. 5449-5461.

Research output: Contribution to journalArticle

Li, Bao Wen ; Osada, Minoru ; Ebina, Yasuo ; Akatsuka, Kosho ; Fukuda, Katsutoshi ; Sasaki, Takayoshi. / High thermal robustness of molecularly thin perovskite nanosheets and implications for superior dielectric properties. In: ACS Nano. 2014 ; Vol. 8, No. 6. pp. 5449-5461.
@article{3af3ca86cd054f84b5dc2f103011128e,
title = "High thermal robustness of molecularly thin perovskite nanosheets and implications for superior dielectric properties",
abstract = "A systematic study has been conducted to examine the thermal stability of layer-by-layer assembled films of perovskite-type nanosheets, (Ca 2Nb3O10 -)n (n = 1-10), which exhibit superior dielectric and insulating properties. In-plane and out-of-plane X-ray diffraction data as well as observations by atomic force microscopy and transmission electron microscopy indicated the high thermal robustness of the nanosheet films. In a monolayer film with an extremely small thickness of ∼2 nm, the nanosheet was stable up to 800°C, the temperature above which segregation into CaNb2O6 and Ca2Nb2O7 began. The critical temperature moderately decreased as the film thickness, or the number of nanosheet layers, increased, and reached 700°C for seven- and 10-layer films, which is comparable to the phase transformation temperature for a bulk phase of the protonic layered oxide of HCa2Nb3O10·1. 5H2O as a precursor of the nanosheet. This thermal stabilization of perovskite-type nanosheets should be associated with restricted nucleation and crystal growth peculiar to such ultrathin 2D bound systems. The stable high-k dielectric response (εr = 210) and highly insulating nature (J < 10-7 A cm-2) remained substantially unchanged even after the nanosheet film was annealed up to 600°C. This study demonstrates the high thermal stability of 2D perovskite-type niobate nanosheets in terms of structure and dielectric properties, which suggests promising potential for future high-k devices operable over a wide temperature range.",
keywords = "layer-by-layer assembly, nanodielectrics, perovskite-type nanosheets, thermal stability",
author = "Li, {Bao Wen} and Minoru Osada and Yasuo Ebina and Kosho Akatsuka and Katsutoshi Fukuda and Takayoshi Sasaki",
year = "2014",
month = "6",
day = "24",
doi = "10.1021/nn502014c",
language = "English",
volume = "8",
pages = "5449--5461",
journal = "ACS Nano",
issn = "1936-0851",
publisher = "American Chemical Society",
number = "6",

}

TY - JOUR

T1 - High thermal robustness of molecularly thin perovskite nanosheets and implications for superior dielectric properties

AU - Li, Bao Wen

AU - Osada, Minoru

AU - Ebina, Yasuo

AU - Akatsuka, Kosho

AU - Fukuda, Katsutoshi

AU - Sasaki, Takayoshi

PY - 2014/6/24

Y1 - 2014/6/24

N2 - A systematic study has been conducted to examine the thermal stability of layer-by-layer assembled films of perovskite-type nanosheets, (Ca 2Nb3O10 -)n (n = 1-10), which exhibit superior dielectric and insulating properties. In-plane and out-of-plane X-ray diffraction data as well as observations by atomic force microscopy and transmission electron microscopy indicated the high thermal robustness of the nanosheet films. In a monolayer film with an extremely small thickness of ∼2 nm, the nanosheet was stable up to 800°C, the temperature above which segregation into CaNb2O6 and Ca2Nb2O7 began. The critical temperature moderately decreased as the film thickness, or the number of nanosheet layers, increased, and reached 700°C for seven- and 10-layer films, which is comparable to the phase transformation temperature for a bulk phase of the protonic layered oxide of HCa2Nb3O10·1. 5H2O as a precursor of the nanosheet. This thermal stabilization of perovskite-type nanosheets should be associated with restricted nucleation and crystal growth peculiar to such ultrathin 2D bound systems. The stable high-k dielectric response (εr = 210) and highly insulating nature (J < 10-7 A cm-2) remained substantially unchanged even after the nanosheet film was annealed up to 600°C. This study demonstrates the high thermal stability of 2D perovskite-type niobate nanosheets in terms of structure and dielectric properties, which suggests promising potential for future high-k devices operable over a wide temperature range.

AB - A systematic study has been conducted to examine the thermal stability of layer-by-layer assembled films of perovskite-type nanosheets, (Ca 2Nb3O10 -)n (n = 1-10), which exhibit superior dielectric and insulating properties. In-plane and out-of-plane X-ray diffraction data as well as observations by atomic force microscopy and transmission electron microscopy indicated the high thermal robustness of the nanosheet films. In a monolayer film with an extremely small thickness of ∼2 nm, the nanosheet was stable up to 800°C, the temperature above which segregation into CaNb2O6 and Ca2Nb2O7 began. The critical temperature moderately decreased as the film thickness, or the number of nanosheet layers, increased, and reached 700°C for seven- and 10-layer films, which is comparable to the phase transformation temperature for a bulk phase of the protonic layered oxide of HCa2Nb3O10·1. 5H2O as a precursor of the nanosheet. This thermal stabilization of perovskite-type nanosheets should be associated with restricted nucleation and crystal growth peculiar to such ultrathin 2D bound systems. The stable high-k dielectric response (εr = 210) and highly insulating nature (J < 10-7 A cm-2) remained substantially unchanged even after the nanosheet film was annealed up to 600°C. This study demonstrates the high thermal stability of 2D perovskite-type niobate nanosheets in terms of structure and dielectric properties, which suggests promising potential for future high-k devices operable over a wide temperature range.

KW - layer-by-layer assembly

KW - nanodielectrics

KW - perovskite-type nanosheets

KW - thermal stability

UR - http://www.scopus.com/inward/record.url?scp=84903455100&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84903455100&partnerID=8YFLogxK

U2 - 10.1021/nn502014c

DO - 10.1021/nn502014c

M3 - Article

AN - SCOPUS:84903455100

VL - 8

SP - 5449

EP - 5461

JO - ACS Nano

JF - ACS Nano

SN - 1936-0851

IS - 6

ER -