Title: Complex magnetic order in the decorated spin-chain system ${\mathrm{Rb}}_2{\mathrm{Mn}}_3{\left({\mathrm{MoO}}_4\right)}_3{\left(\mathrm{OH}\right)}_2$

Abstract

The macroscopic magnetic properties and microscopic magnetic structure of Rb₂Mn₃(MoO₄)₃ (OH)₂ (space group Pn ma) are investigated by magnetization, heat capacity, and single-crystal neutron diffraction measurements. The compound's crystal structure contains bond-alternating [Mn₃ O₁₁] ^∞ chains along the b axis, formed by isosceles triangles of Mn ions occupying two crystallographically nonequivalent sites (the Mn1 site on the base and Mn2 site on the vertex). These chains are only weakly linked to each other by nonmagnetic oxyanions. Both superconducting quantum interference device magnetometry and neutron diffraction experiments show two successive magnetic transitions as a function of temperature. On cooling, it transitions from a paramagnetic phase into an incommensurate phase below 4.5 K with a magnetic wave vector near k₁ = ( 0 , 0.46 , 0 ). An additional commensurate antiferromagnetically ordered component arises with k₂ = ( 0, 0, 0), forming a complex magnetic structure below 3.5 K with two different propagation vectors of different stars. On further cooling, the incommensurate wave vector undergoes a lock-in transition below 2.3 K. The experimental results suggest that the magnetic superspace group is Pnma. 1' (0b0) s0ss for the single- k incommensurate phase and is Pn' m a ( 0 b 0 )more » 00 s for the two- k magnetic phase. We propose a simplified magnetic structure model taking into account the major ordered contributions, where the commensurate k₂ defines the ordering of the c-axis component of the Mn1 magnetic moment, while the incommensurate k₁ describes the ordering of the ab -plane components of both Mn1 and Mn2 moments into elliptical cycloids.« less

Authors:

Liu, Yaohua  ^[1];

• Search DOE PAGES for author "Liu, Yaohua"
• Search DOE PAGES for ORCID "0000-0002-5867-5065"

Sanjeewa, Liurukara D.  ^[1];

• Search DOE PAGES for author "Sanjeewa, Liurukara D."
• Search DOE PAGES for ORCID "0000-0002-3293-7370"

Garlea, V. Ovidiu  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-5322-7271"

Smith Pellizzeri, Tiffany M. ^[2]; Kolis, Joseph W. ^[3]; Sefat, Athena S.  ^[1]

• Search DOE PAGES for author "Sefat, Athena S."
• Search DOE PAGES for ORCID "0000-0002-5596-3504"

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+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Clemson Univ., SC (United States); Eastern Illinois Univ., Charleston, IL (United States)
3. Clemson Univ., SC (United States)

Publication Date:

Mon Feb 24 00:00:00 EST 2020

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1606870

Alternate Identifier(s):

OSTI ID: 1601701

Grant/Contract Number:  

AC05-00OR22725; FG02-13ER41967

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review B

Additional Journal Information:

Journal Volume: 101; Journal Issue: 6; Journal ID: ISSN 2469-9950

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY