DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Femtosecond Measurements Of Size-Dependent Spin Crossover In FeII(pyz)Pt(CN)4 Nanocrystals

Abstract

We report a femtosecond time-resolved spectroscopic study of size-dependent dynamics in nanocrystals (NCs) of Fe(pyz)Pt(CN)4. We observe that smaller NCs (123 or 78 nm cross section and < 25 nm thickness) exhibit signatures of spin crossover (SCO) with time constants of ~ 5-10 ps whereas larger NCs with 375 nm cross section and 43 nm thickness exhibit a weaker SCO signature accompanied by strong spectral shifting on a ~20 ps time scale. For the small NCs, the fast dynamics appear to result from thermal promotion of residual low-spin states to high-spin states following nonradiative decay, and the size dependence is postulated to arise from differing high-spin vs low-spin fractions in domains residing in strained surface regions. The SCO is less efficient in larger NCs owing to their larger size and hence lower residual LS/HS fractions. Our results suggest that size-dependent dynamics can be controlled by tuning surface energy in NCs with dimensions below ~25 nm for use in energy harvesting, spin switching, and other applications.

Authors:
 [1];  [2];  [1];  [3];  [2];  [2];  [4]
  1. Univ. of Colorado, Boulder, CO (United States). JILA
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  3. National Inst. of Standards and Technology (NIST), Boulder, CO (United States)
  4. Univ. of Colorado, Boulder, CO (United States). JILA and Dept. of Chemistry and Biochemistry
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1239050
Report Number(s):
NREL/JA-5900-64263
Journal ID: ISSN 1948-7185
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry Letters
Additional Journal Information:
Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 1948-7185
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 77 NANOSCIENCE AND NANOTECHNOLOGY; femtosecond; spin-crossover; nanocrystals; time-resolved spectroscopy; high spin; low spin; transient absorption

Citation Formats

Sagar, D. M., Baddour, Frederick G., Konold, Patrick, Ullom, Joel, Ruddy, Daniel A., Johnson, Justin C., and Jimenez, Ralph. Femtosecond Measurements Of Size-Dependent Spin Crossover In FeII(pyz)Pt(CN)4 Nanocrystals. United States: N. p., 2016. Web. doi:10.1021/acs.jpclett.5b02435.
Sagar, D. M., Baddour, Frederick G., Konold, Patrick, Ullom, Joel, Ruddy, Daniel A., Johnson, Justin C., & Jimenez, Ralph. Femtosecond Measurements Of Size-Dependent Spin Crossover In FeII(pyz)Pt(CN)4 Nanocrystals. United States. https://doi.org/10.1021/acs.jpclett.5b02435
Sagar, D. M., Baddour, Frederick G., Konold, Patrick, Ullom, Joel, Ruddy, Daniel A., Johnson, Justin C., and Jimenez, Ralph. Thu . "Femtosecond Measurements Of Size-Dependent Spin Crossover In FeII(pyz)Pt(CN)4 Nanocrystals". United States. https://doi.org/10.1021/acs.jpclett.5b02435. https://www.osti.gov/servlets/purl/1239050.
@article{osti_1239050,
title = {Femtosecond Measurements Of Size-Dependent Spin Crossover In FeII(pyz)Pt(CN)4 Nanocrystals},
author = {Sagar, D. M. and Baddour, Frederick G. and Konold, Patrick and Ullom, Joel and Ruddy, Daniel A. and Johnson, Justin C. and Jimenez, Ralph},
abstractNote = {We report a femtosecond time-resolved spectroscopic study of size-dependent dynamics in nanocrystals (NCs) of Fe(pyz)Pt(CN)4. We observe that smaller NCs (123 or 78 nm cross section and < 25 nm thickness) exhibit signatures of spin crossover (SCO) with time constants of ~ 5-10 ps whereas larger NCs with 375 nm cross section and 43 nm thickness exhibit a weaker SCO signature accompanied by strong spectral shifting on a ~20 ps time scale. For the small NCs, the fast dynamics appear to result from thermal promotion of residual low-spin states to high-spin states following nonradiative decay, and the size dependence is postulated to arise from differing high-spin vs low-spin fractions in domains residing in strained surface regions. The SCO is less efficient in larger NCs owing to their larger size and hence lower residual LS/HS fractions. Our results suggest that size-dependent dynamics can be controlled by tuning surface energy in NCs with dimensions below ~25 nm for use in energy harvesting, spin switching, and other applications.},
doi = {10.1021/acs.jpclett.5b02435},
journal = {Journal of Physical Chemistry Letters},
number = 1,
volume = 7,
place = {United States},
year = {2016},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Spin-Crossover Nanocrystals with Magnetic, Optical, and Structural Bistability Near Room Temperature
journal, August 2008

  • Boldog, Ishtvan; Gaspar, Ana B.; Martínez, Víctor
  • Angewandte Chemie International Edition, Vol. 47, Issue 34
  • DOI: 10.1002/anie.200801673

Metal Dilution Effects on the Spin-Crossover Properties of the Three-Dimensional Coordination Polymer Fe(pyrazine)[Pt(CN) 4 ]
journal, August 2005

  • Tayagaki, Takeshi; Galet, Ana; Molnár, Gábor
  • The Journal of Physical Chemistry B, Vol. 109, Issue 31
  • DOI: 10.1021/jp0521611

Photoswitchable spin crossover nanoparticles
journal, January 2014


Single-Laser-Shot-Induced Complete Bidirectional Spin Transition at Room Temperature in Single Crystals of (Fe II (pyrazine)(Pt(CN) 4 ))
journal, July 2008

  • Cobo, Saioa; Ostrovskii, Denis; Bonhommeau, Sébastien
  • Journal of the American Chemical Society, Vol. 130, Issue 28
  • DOI: 10.1021/ja800878f

Light-induced spin crossover in Fe(II)-based complexes: The full photocycle unraveled by ultrafast optical and X-ray spectroscopies
journal, November 2010

  • Cannizzo, A.; Milne, C. J.; Consani, C.
  • Coordination Chemistry Reviews, Vol. 254, Issue 21-22
  • DOI: 10.1016/j.ccr.2009.12.007

Sub-50-fs photoinduced spin crossover in [Fe(bpy)3]2+
journal, July 2015

  • Auböck, Gerald; Chergui, Majed
  • Nature Chemistry, Vol. 7, Issue 8
  • DOI: 10.1038/nchem.2305

Femtosecond XANES Study of the Light-Induced Spin Crossover Dynamics in an Iron(II) Complex
journal, January 2009


Femtosecond Absorption Spectroscopy of Transition Metal Charge-Transfer Complexes
journal, December 2003

  • McCusker, James K.
  • Accounts of Chemical Research, Vol. 36, Issue 12
  • DOI: 10.1021/ar030111d

Structural Determination of a Short-Lived Excited Iron(II) Complex by Picosecond X-Ray Absorption Spectroscopy
journal, February 2007


Ultrafast cascading theory of intersystem crossings in transition-metal complexes
journal, August 2010


Intersystem crossing in the [Fe(ptz) 6 ](BF 4 ) 2 spin crossover system (ptz=1‐propyltetrazole)
journal, February 1991

  • Hauser, Andreas
  • The Journal of Chemical Physics, Vol. 94, Issue 4
  • DOI: 10.1063/1.459851

Observation of 1 MLCT and 3 MLCT Excited States in Quadruply Bonded Mo 2 and W 2 Complexes
journal, December 2005

  • Byrnes, Matthew J.; Chisholm, Malcolm H.; Gallucci, Judith A.
  • Journal of the American Chemical Society, Vol. 127, Issue 49
  • DOI: 10.1021/ja055136h

Femtosecond Excited-State Dynamics of an Iron(II) Polypyridyl Solar Cell Sensitizer Model
journal, May 2000

  • Monat, Jeremy E.; McCusker, James K.
  • Journal of the American Chemical Society, Vol. 122, Issue 17
  • DOI: 10.1021/ja992436o

Spin Crossover Phenomenon in Nanocrystals and Nanoparticles of [Fe(3-Fpy) 2 M(CN) 4 ] (M II = Ni, Pd, Pt) Two-Dimensional Coordination Polymers
journal, June 2010

  • Martínez, Víctor; Boldog, Ishtvan; Gaspar, Ana Belén
  • Chemistry of Materials, Vol. 22, Issue 14
  • DOI: 10.1021/cm101022u

Femtosecond Spin-State Photoswitching of Molecular Nanocrystals Evidenced by Optical Spectroscopy
journal, June 2012

  • Bertoni, Roman; Lorenc, Maciej; Tissot, Antoine
  • Angewandte Chemie International Edition, Vol. 51, Issue 30
  • DOI: 10.1002/anie.201202215

Enhanced Cooperative Interactions at the Nanoscale in Spin-Crossover Materials with a First-Order Phase Transition
journal, June 2013


Finite size effects in molecular spin crossover materials
journal, January 2014

  • Mikolasek, Mirko; Félix, Gautier; Nicolazzi, William
  • New Journal of Chemistry, Vol. 38, Issue 5
  • DOI: 10.1039/c3nj01268a

Structural Investigation of the High Spin→Low Spin Relaxation Dynamics of the Porous Coordination Network [Fe(pz)Pt(CN) 4 ]⋅2.6 H 2 O
journal, January 2015

  • Delgado, Teresa; Tissot, Antoine; Besnard, Céline
  • Chemistry - A European Journal, Vol. 21, Issue 9
  • DOI: 10.1002/chem.201405405

Matrix-dependent cooperativity in spin crossover Fe(pyrazine)Pt(CN)4 nanoparticles
journal, January 2011

  • Raza, Yousuf; Volatron, Florence; Moldovan, Simona
  • Chemical Communications, Vol. 47, Issue 41
  • DOI: 10.1039/c1cc14463d

Enhanced bistability by guest inclusion in Fe(ii) spin crossover porous coordination polymers
journal, January 2012

  • Muñoz Lara, Francisco J.; Gaspar, Ana B.; Aravena, Daniel
  • Chemical Communications, Vol. 48, Issue 39
  • DOI: 10.1039/c2cc31048a

Single-nanoparticle phase transitions visualized by four-dimensional electron microscopy
journal, April 2013

  • van der Veen, Renske M.; Kwon, Oh-Hoon; Tissot, Antoine
  • Nature Chemistry, Vol. 5, Issue 5
  • DOI: 10.1038/nchem.1622

Nanocrystals of Fe(phen) 2 (NCS) 2 and the size-dependent spin-crossover characteristics
journal, January 2015

  • Laisney, J.; Tissot, A.; Molnár, G.
  • Dalton Transactions, Vol. 44, Issue 39
  • DOI: 10.1039/C5DT02840J

Semiconductor Quantum Dots and Quantum Dot Arrays and Applications of Multiple Exciton Generation to Third-Generation Photovoltaic Solar Cells
journal, November 2010

  • Nozik, A. J.; Beard, M. C.; Luther, J. M.
  • Chemical Reviews, Vol. 110, Issue 11
  • DOI: 10.1021/cr900289f

Towards longer-lived metal-to-ligand charge transfer states of iron(ii) complexes: an N-heterocyclic carbene approach
journal, January 2013

  • Liu, Yizhu; Harlang, Tobias; Canton, Sophie E.
  • Chemical Communications, Vol. 49, Issue 57
  • DOI: 10.1039/c3cc43833c

Mechanism for optical switching of the spin crossover [Fe(NH2-trz)3](Br)2·3H2O compound at room temperature
journal, January 2010

  • Fouché, Olivier; Degert, Jérôme; Jonusauskas, Gediminas
  • Physical Chemistry Chemical Physics, Vol. 12, Issue 12
  • DOI: 10.1039/b921984f

Femtosecond Time-Resolved Optical and Raman Spectroscopy of Photoinduced Spin Crossover: Temporal Resolution of Low-to-High Spin Optical Switching
journal, October 2008

  • Smeigh, Amanda L.; Creelman, Mark; Mathies, Richard A.
  • Journal of the American Chemical Society, Vol. 130, Issue 43
  • DOI: 10.1021/ja805949s

Works referencing / citing this record:

Finite Size Effects on the Switching Dynamics of Spin‐Crossover Thin Films Photoexcited by a Femtosecond Laser Pulse
journal, April 2019

  • Ridier, Karl; Bas, Alin‐Ciprian; Shalabaeva, Victoria
  • Advanced Materials, Vol. 31, Issue 25
  • DOI: 10.1002/adma.201901361