Title: New kagome prototype materials: discovery of ${\mathrm{KV}}_3{\mathrm{Sb}}_5,{\mathrm{RbV}}_3{\mathrm{Sb}}_5$ , and ${\mathrm{CsV}}_3{\mathrm{Sb}}_5$

Abstract

In this work, we present our discovery and characterization of a new kagome prototype structure, KV₃Sb₅. We also present the discovery of the isostructural compounds RbV₃Sb₅ and CsV₃Sb₅. All materials exhibit a structurally perfect two-dimensional kagome net of vanadium. Density-functional theory calculations indicate that the materials are metallic, with the Fermi level in close proximity to several Dirac points. Powder and single-crystal syntheses are presented, with postsynthetic treatments shown to deintercalate potassium from single crystals of KV₃Sb₅. Considering the proximity to Dirac points, deintercalation provides a convenient means to tune the Fermi level. Magnetization measurements indicate that KV₃Sb₅ exhibits behavior consistent with a the Curie-Weiss model at high temperatures, although the effective moment is low (0.22μ_B per vanadium ion). An anomaly is observed in both magnetization and heat capacity measurements at 80 K, below which the moment is largely quenched. Elastic neutron scattering measurements find no obvious evidence of long-range or short-range magnetic ordering below 80 K. The possibility of an orbital-ordering event is considered. Single-crystal resistivity measurements show the effect of deintercalation on the electron transport and allow estimation of the Kadowaki-Woods ratio in KV₃Sb₅. We find that A/γ²~61μOhm cm mol²_FU K²J^-2, suggesting that correlated electron transport may bemore » possible. KV₃Sb₅ and its cogeners RbV₃Sb₅ and CsV₃Sb₅ represent a new family of kagome metals, and our results demonstrate that they deserve further study as potential model systems.« less

Authors:

Ortiz, Brenden R. ^[1]; Gomes, Lídia C. ^[2]; Morey, Jennifer R. ^[3]; Winiarski, Michal ^[4]; Bordelon, Mitchell ^[5]; Mangum, John S. ^[6]; Oswald, Iain W. H. ^[7]; Rodriguez-Rivera, Jose A. ^[8]; Neilson, James R. ^[7]; Wilson, Stephen D. ^[5]; Ertekin, Elif ^[2]; McQueen, Tyrel M. ^[3]; Toberer, Eric S. ^[6]

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+ Show Author Affiliations

1. Colorado School of Mines, Golden, CO (United States); Univ. of California, Santa Barbara, CA (United States)
2. Univ. of Illinois at Urbana-Champaign, IL (United States); National Center for Supercomputing Applications, Urbana, IL (United States)
3. Johns Hopkins Univ., Baltimore, MD (United States)
4. Johns Hopkins Univ., Baltimore, MD (United States); Gdansk Univ. of Technology (Poland)
5. Univ. of California, Santa Barbara, CA (United States)
6. Colorado School of Mines, Golden, CO (United States)
7. Colorado State Univ., Fort Collins, CO (United States)
8. NIST Center for Neutron Research, Gaithersburg, MD (United States); Univ. of Maryland, College Park, MD (United States)

Publication Date:

Mon Sep 16 00:00:00 EDT 2019

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Institute for Quantum Matter (IQM); Univ. of California, Santa Barbara, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)

OSTI Identifier:

1594783

Alternate Identifier(s):

OSTI ID: 1562170

Grant/Contract Number:  

SC0017752; SC0019331; AC-06CH11357; 1729594; 1729149; 147106; AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Materials

Additional Journal Information:

Journal Volume: 3; Journal Issue: 9; Journal ID: ISSN 2475-9953

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE