Imbalanced spin coupling in the copper hexamer compounds <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>A</mi><mn>2</mn></msub><msub><mi>Cu</mi><mn>3</mn></msub><mi mathvariant="normal">O</mi><msub><mrow><mo>(</mo><msub><mi>SO</mi><mn>4</mn></msub><mo>)</mo></mrow><mn>3</mn></msub></mrow><mo>(</mo><mrow><msub><mi>A</mi><mn>2</mn></msub><mo>=</mo><msub><mi>Na</mi><mn>2</mn></msub></mrow><mo>,</mo><mi>NaK</mi><mo>,</mo><msub><mi mathvariant="normal">K</mi><mn>2</mn></msub><mo>)</mo></math>

A. Furrer; A. Podlesnyak; E. Pomjakushina; V. Pomjakushin

doi:10.1103/PhysRevB.104.L220401

Letter

Imbalanced spin coupling in the copper hexamer compounds $A_{2} {Cu}_{3} O {({SO}_{4})}_{3} (A_{2} = {Na}_{2}, NaK, K_{2})$

A. Furrer ¹, A. Podlesnyak ², E. Pomjakushina ³, and V. Pomjakushin¹

¹Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
²Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
³Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland

PDF

Phys. Rev. B 104, L220401 – Published 2 December, 2021

DOI: https://doi.org/10.1103/PhysRevB.104.L220401

Abstract

The minerals $A_{2} {Cu}_{3} O {({SO}_{4})}_{3} (A_{2} = {Na}_{2}, NaK, K_{2})$ constitute quantum spin systems with copper hexamers as basic structural units. Strong intrahexamer spin couplings give rise to an effective triplet ground state. Weak interhexamer spin couplings are responsible for two-dimensional long-range magnetic order in the ( $b, c$ ) plane below $3.0 < T_{c} < 4.7 K$ . We investigated the magnetic excitations at $T = 1.5$ K by inelastic neutron scattering (INS). The INS technique was based on the observation of wave vector dependent slices in reciprocal space in order to selectively probe the magnetic signals in different Brillouin zones with different weight. Due to the imbalance of the spin couplings, the data analysis relies on a model in which the interhexamer spin couplings are treated perturbatively on top of the exact $S = 1$ ground state. The interhexamer spin couplings turn out to be ferromagnetic.

Physical Review B

Export citation

Export citation

Imbalanced spin coupling in the copper hexamer compounds $A_{2} {Cu}_{3} O {({SO}_{4})}_{3} (A_{2} = {Na}_{2}, NaK, K_{2})$

Abstract

Physics Subject Headings (PhySH)

Authorization Required

Other Options

Supplemental Material (Subscription Required)

References (Subscription Required)

Outline

Information

Filter

Filter

Article Lookup

Enter a citation

Imbalanced spin coupling in the copper hexamer compounds A2Cu3O(SO4)3(A2=Na2,NaK,K2)

Abstract

Physics Subject Headings (PhySH)

Authorization Required

Log in via your institution

Log in via APS Member Subscription

Other Options

Supplemental Material (Subscription Required)

References (Subscription Required)

Imbalanced spin coupling in the copper hexamer compounds $A_{2} {Cu}_{3} O {({SO}_{4})}_{3} (A_{2} = {Na}_{2}, NaK, K_{2})$