Electron Small Polaron and Magnetic Interactions Direct Anisotropic Growth of Silicon-Doped Hematite Nanocrystals

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10425671" target="_blank" >RIV/00216208:11320/20:10425671 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/20:00538296 RIV/61989592:15310/20:73603901

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=yZX3-uOVYa" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=yZX3-uOVYa</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.cgd.0c00496" target="_blank" >10.1021/acs.cgd.0c00496</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Electron Small Polaron and Magnetic Interactions Direct Anisotropic Growth of Silicon-Doped Hematite Nanocrystals

Popis výsledku v původním jazyce

Hematite (alpha-Fe2O3) is a promising and Earth-abundant material for solar fuel production, and Si-doping has been employed as a general strategy to improve its performance. However, an atomistic description that reconciles the modifications that Si-doping induces on the morphology, crystalline lattice, and electronic and magnetic properties of alpha-Fe2O3 has remained elusive. Here we report on the role of electron small polarons in driving the morphological transition from nearly rounded-shaped to nanowire nanocrystals in Si-doped hematite alpha-Fe2O3. Electron small polaron formation is evidenced by the formation of Fe2+ and the increase of FeO6 distortion at increasing Si content. Local analysis via pair distribution function highlights an unreported crossover from small to large polarons, which affects the correlation length of the polaronic distortion from short to average scales. Ferromagnetic double exchange interactions between Fe2+/Fe3+ species are found to be the driving force of the crossover, constraining the chaining of chemical bonds along the [110] crystallographic direction. This promotes the increase in the reticular density of Fe atoms along the hematite basal plane only, which boosts the anisotropic growth of nanocrystals with more extended [110] facets. Our results show that magnetic and electronic interactions drive preferential crystallographic growth in Si-doped alpha-Fe2O3, thus providing new insights for the nanoscale structural design of efficient solar fuel devices.

Název v anglickém jazyce

Electron Small Polaron and Magnetic Interactions Direct Anisotropic Growth of Silicon-Doped Hematite Nanocrystals

Popis výsledku anglicky

Hematite (alpha-Fe2O3) is a promising and Earth-abundant material for solar fuel production, and Si-doping has been employed as a general strategy to improve its performance. However, an atomistic description that reconciles the modifications that Si-doping induces on the morphology, crystalline lattice, and electronic and magnetic properties of alpha-Fe2O3 has remained elusive. Here we report on the role of electron small polarons in driving the morphological transition from nearly rounded-shaped to nanowire nanocrystals in Si-doped hematite alpha-Fe2O3. Electron small polaron formation is evidenced by the formation of Fe2+ and the increase of FeO6 distortion at increasing Si content. Local analysis via pair distribution function highlights an unreported crossover from small to large polarons, which affects the correlation length of the polaronic distortion from short to average scales. Ferromagnetic double exchange interactions between Fe2+/Fe3+ species are found to be the driving force of the crossover, constraining the chaining of chemical bonds along the [110] crystallographic direction. This promotes the increase in the reticular density of Fe atoms along the hematite basal plane only, which boosts the anisotropic growth of nanocrystals with more extended [110] facets. Our results show that magnetic and electronic interactions drive preferential crystallographic growth in Si-doped alpha-Fe2O3, thus providing new insights for the nanoscale structural design of efficient solar fuel devices.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

—

Návaznosti

—

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Crystal Growth and Design

ISSN

1528-7483

e-ISSN

—

Svazek periodika

20

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

4719-4730

Kód UT WoS článku

000546699900054

EID výsledku v databázi Scopus

2-s2.0-85090090786