Dynamical Bonding Driving Mixed Valency in a Metal Boride

Robinson, Paul J.; Munarriz, Julen; Valentine, Michael E.; Granmoe, Austin; Drichko, Natalia; Chamorro, Juan R.; Rosa, Priscila F.; McQueen, Tyrel M.; Alexandrova, Anastassia N.

doi:10.1002/anie.202000945

Title: Dynamical Bonding Driving Mixed Valency in a Metal Boride

Abstract

Abstract Samarium hexaboride is an anomaly, having many exotic and seemingly mutually incompatible properties. It was proposed to be a mixed‐valent semiconductor, and later a topological Kondo insulator, and yet has a Fermi surface despite being an insulator. We propose a new and unified understanding of SmB ₆ centered on the hitherto unrecognized dynamical bonding effect: the coexistence of two Sm−B bonding modes within SmB ₆ , corresponding to different oxidation states of the Sm. The mixed valency arises in SmB ₆ from thermal population of these distinct minima enabled by motion of B. Our model simultaneously explains the thermal valence fluctuations, appearance of magnetic Fermi surface, excess entropy at low temperatures, pressure‐induced phase transitions, and related features in Raman spectra and their unexpected dependence on temperature and boron isotope.

Authors:

^[1];

^[2]; Valentine, Michael E. ^[3]; Granmoe, Austin ^[3]; Drichko, Natalia ^[3]; Chamorro, Juan R. ^[3]; Rosa, Priscila F. ^[4]; McQueen, Tyrel M. ^[3];

^[2]

Univ. of California, Los Angeles, CA (United States); Columbia Univ., New York, NY (United States)
Univ. of California, Los Angeles, CA (United States)
Johns Hopkins Univ., Baltimore, MD (United States)
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:: 2020-04-06

Research Org.:: Energy Frontier Research Centers (EFRC) (United States). Institute for Quantum Matter (IQM); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1671085

Alternate Identifier(s):: OSTI ID: 1608371

Report Number(s):: LA-UR-19-30421
Journal ID: ISSN 1433-7851

Grant/Contract Number:: 89233218CNA000001; SC0019331

Resource Type:: Accepted Manuscript

Journal Name:: Angewandte Chemie (International Edition)

Additional Journal Information:: Journal Name: Angewandte Chemie (International Edition); Journal Volume: 59; Journal Issue: 27; Journal ID: ISSN 1433-7851

Publisher:: Wiley

Country of Publication:: United States

Language:: English

Subject:: 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Material Science; chemical bonding; mixed valency; pressure induced phase transitions; Raman spectroscopy; samarium hexaboride

Citation Formats


                    Robinson, Paul J., Munarriz, Julen, Valentine, Michael E., Granmoe, Austin, Drichko, Natalia, Chamorro, Juan R., Rosa, Priscila F., McQueen, Tyrel M., and Alexandrova, Anastassia N. Dynamical Bonding Driving Mixed Valency in a Metal Boride.  United States: N. p., 2020. 
Web.  doi:10.1002/anie.202000945.

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                    Robinson, Paul J., Munarriz, Julen, Valentine, Michael E., Granmoe, Austin, Drichko, Natalia, Chamorro, Juan R., Rosa, Priscila F., McQueen, Tyrel M., & Alexandrova, Anastassia N. Dynamical Bonding Driving Mixed Valency in a Metal Boride.  United States.  https://doi.org/10.1002/anie.202000945

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                    Robinson, Paul J., Munarriz, Julen, Valentine, Michael E., Granmoe, Austin, Drichko, Natalia, Chamorro, Juan R., Rosa, Priscila F., McQueen, Tyrel M., and Alexandrova, Anastassia N. Mon .  
"Dynamical Bonding Driving Mixed Valency in a Metal Boride".  United States.  https://doi.org/10.1002/anie.202000945.  https://www.osti.gov/servlets/purl/1671085.

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@article{osti_1671085,

  title        = {Dynamical Bonding Driving Mixed Valency in a Metal Boride},

  author       = {Robinson, Paul J. and Munarriz, Julen and Valentine, Michael E. and Granmoe, Austin and Drichko, Natalia and Chamorro, Juan R. and Rosa, Priscila F. and McQueen, Tyrel M. and Alexandrova, Anastassia N.},

  abstractNote = {Abstract Samarium hexaboride is an anomaly, having many exotic and seemingly mutually incompatible properties. It was proposed to be a mixed‐valent semiconductor, and later a topological Kondo insulator, and yet has a Fermi surface despite being an insulator. We propose a new and unified understanding of SmB 6 centered on the hitherto unrecognized dynamical bonding effect: the coexistence of two Sm−B bonding modes within SmB 6 , corresponding to different oxidation states of the Sm. The mixed valency arises in SmB 6 from thermal population of these distinct minima enabled by motion of B. Our model simultaneously explains the thermal valence fluctuations, appearance of magnetic Fermi surface, excess entropy at low temperatures, pressure‐induced phase transitions, and related features in Raman spectra and their unexpected dependence on temperature and boron isotope.},

  doi          = {10.1002/anie.202000945},

  journal      = {Angewandte Chemie (International Edition)},

  number       = 27,

  volume       = 59,

  place        = {United States},

  year         = {2020},

  month        = {4}

}

Copy to clipboard

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Title: Dynamical Bonding Driving Mixed Valency in a Metal Boride

Abstract

Citation Formats

Surface-dominated conduction up to 240 K in the Kondo insulator SmB6 under strain journal, April 2017

Temperature dependence of Sm valence in SmB 6 studied by X-ray absorption spectroscopy journal, June 2009

Chemical Bonding of Crystalline LnB 6 (Ln = La–Lu) and Its Relationship with Ln 2 B 8 Gas-Phase Complexes journal, September 2018

Design of hard crystals journal, January 2006

Two-dimensional Fermi surfaces in Kondo insulator SmB 6 journal, December 2014

Sm B 6 : Kondo Insulator or Exotic Metal? journal, February 1995

Additional energy scale in SmB6 at low-temperature journal, December 2016

How Chemistry and Physics Meet in the Solid State journal, September 1987

Topological surface state in the Kondo insulator samarium hexaboride journal, March 2014

Pressure-Resistant Intermediate Valence in the Kondo Insulator SmB 6 journal, April 2016

Excitons in topological Kondo insulators: Theory of thermodynamic and transport anomalies in SmB 6 journal, March 2017

Unconventional Fermi surface in an insulating state journal, July 2015

Advancements in the Search for Superhard Ultra-Incompressible Metal Borides journal, November 2009

Theory of mixed valence: Metals or small gap insulators (invited) journal, January 1979

Effects of Configuration Interaction on Intensities and Phase Shifts journal, December 1961

Quantum-chemical insights into mixed-valence systems: within and beyond the Robin–Day scheme journal, January 2014

Valence transitions and intermediate valence states in rare earth and actinide materials journal, March 1979

Harder than diamond: Dreams and reality journal, January 2002

Study of valence mixing in SmB 6 by x-ray photoelectron spectroscopy journal, November 1976

Kondo Breakdown and Quantum Oscillations in SmB 6 journal, January 2016

Metal-Insulator Transitions: A Simple Theoretical Model journal, October 1970

Understanding How Bonding Controls Strength Anisotropy in Hard Materials by Comparing the High-Pressure Behavior of Orthorhombic and Tetragonal Tungsten Monoboride journal, February 2018

Topological Kondo Insulators journal, March 2016

The Metallic State journal, June 1948

Die Begegnung von Chemie und Physik im Festkörper journal, September 1987

Mystery of Three Borides: Differential Metal–Boron Bonding Governing Superhard Structures journal, November 2017

Breakdown of the Kondo insulating state in SmB 6 by introducing Sm vacancies journal, August 2016

High borides: determining the features and details of lattice dynamics from neutron spectroscopy journal, April 2015

SmB 6 – Cluster Anion: Covalency Involving f Orbitals journal, February 2017

Physical Properties of Sm B 6 journal, March 1971

Raman scattering investigation of R B 6 ( R = Ca , La, Ce, Pr, Sm, Gd, Dy, and Yb) journal, December 2003

Elastic, electronic and thermal properties of topological insulator SmB 6 : first-principles calculations journal, February 2017

Topological surface states interacting with bulk excitations in the Kondo insulator SmB 6 revealed via planar tunneling spectroscopy journal, May 2016

Observation of possible topological in-gap surface states in the Kondo insulator SmB6 by photoemission journal, December 2013

Skyrme Insulators: Insulators at the Brink of Superconductivity journal, August 2017

Fermi surface in the absence of a Fermi liquid in the Kondo insulator SmB6 journal, October 2017

The Metallic State journal, June 1948

Skyrme insulators: insulators at the brink of superconductivity text, January 2017

Surface-dominated conduction up to 240 K in the Kondo insulator SmB6 under strain
journal, April 2017

Temperature dependence of Sm valence in SmB ₆ studied by X-ray absorption spectroscopy
journal, June 2009

Chemical Bonding of Crystalline LnB ₆ (Ln = La–Lu) and Its Relationship with Ln ₂ B ₈ Gas-Phase Complexes
journal, September 2018

Design of hard crystals
journal, January 2006

Two-dimensional Fermi surfaces in Kondo insulator SmB ₆
journal, December 2014

Sm $B_{6}$ : Kondo Insulator or Exotic Metal?
journal, February 1995

Additional energy scale in SmB6 at low-temperature
journal, December 2016

How Chemistry and Physics Meet in the Solid State
journal, September 1987

Topological surface state in the Kondo insulator samarium hexaboride
journal, March 2014

Pressure-Resistant Intermediate Valence in the Kondo Insulator ${SmB}_{6}$
journal, April 2016

Excitons in topological Kondo insulators: Theory of thermodynamic and transport anomalies in ${SmB}_{6}$
journal, March 2017

Unconventional Fermi surface in an insulating state
journal, July 2015

Advancements in the Search for Superhard Ultra-Incompressible Metal Borides
journal, November 2009

Theory of mixed valence: Metals or small gap insulators (invited)
journal, January 1979

Effects of Configuration Interaction on Intensities and Phase Shifts
journal, December 1961

Quantum-chemical insights into mixed-valence systems: within and beyond the Robin–Day scheme
journal, January 2014

Valence transitions and intermediate valence states in rare earth and actinide materials
journal, March 1979

Harder than diamond: Dreams and reality
journal, January 2002

Study of valence mixing in ${SmB}_{6}$ by x-ray photoelectron spectroscopy
journal, November 1976

Kondo Breakdown and Quantum Oscillations in ${SmB}_{6}$
journal, January 2016

Metal-Insulator Transitions: A Simple Theoretical Model
journal, October 1970

Understanding How Bonding Controls Strength Anisotropy in Hard Materials by Comparing the High-Pressure Behavior of Orthorhombic and Tetragonal Tungsten Monoboride
journal, February 2018

Topological Kondo Insulators
journal, March 2016

The Metallic State
journal, June 1948

Die Begegnung von Chemie und Physik im Festkörper
journal, September 1987

Mystery of Three Borides: Differential Metal–Boron Bonding Governing Superhard Structures
journal, November 2017

Breakdown of the Kondo insulating state in ${SmB}_{6}$ by introducing Sm vacancies
journal, August 2016

High borides: determining the features and details of lattice dynamics from neutron spectroscopy
journal, April 2015

SmB ₆ ^– Cluster Anion: Covalency Involving f Orbitals
journal, February 2017

Physical Properties of Sm $B_{6}$
journal, March 1971

Raman scattering investigation of $R B_{6}$ $(R = Ca,$ La, Ce, Pr, Sm, Gd, Dy, and Yb)
journal, December 2003

Elastic, electronic and thermal properties of topological insulator SmB ₆ : first-principles calculations
journal, February 2017

Topological surface states interacting with bulk excitations in the Kondo insulator SmB ₆ revealed via planar tunneling spectroscopy
journal, May 2016

Observation of possible topological in-gap surface states in the Kondo insulator SmB6 by photoemission
journal, December 2013

Skyrme Insulators: Insulators at the Brink of Superconductivity
journal, August 2017

Fermi surface in the absence of a Fermi liquid in the Kondo insulator SmB6
journal, October 2017

The Metallic State
journal, June 1948

Skyrme insulators: insulators at the brink of superconductivity
text, January 2017