English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We report magnetic susceptibility \chi, isothermal magnetization M, heatcapacity C_p and electrical resistivity \rho measurements on undoped EuMn2As2and K-doped Eu0.96K0.04Mn2As2 and Eu0.93K0.07Mn2As2 single crystals with thetrigonal CaAl2Si2-type structure as a function of temperature T and magneticfield H. EuMn2As2 has an insulating ground state with an activation energy of52 meV and exhibits antiferromagnetic (AFM) ordering of the Eu+2 spins S=7/2 atT_N1 = 15 K from C_p(T) and \chi(T) data with a likely spin-reorientationtransition at T_N2 = 5.0 K. The Mn+2 3d5 spins-5/2 exhibit AFM ordering at T_N= 142 K from all three types of measurements. The M(H) isotherm and \chi(T)data indicate that the Eu AFM structure is both noncollinear and noncoplanar.The AFM structure of the Mn spins is also unclear. A 4% substitution of K forEu in Eu0.96K0.04Mn2As2 is sufficient to induce a metallic ground state.Evidence is found for a difference in the AFM structure of the Eu moments inthe metallic crystals from that of undoped EuMn2As2 versus both T and H. Formetallic Eu0.96K0.04Mn2As2 and Eu0.93K0.07Mn2As2, an anomalous S-shape Tdependence of \rho related to the Mn magnetism is found. Upon cooling from 200K, \rho exhibits a strong negative curvature, reaches maximum positive slope atthe Mn T_N ~ 150 K, and then continues to decrease but more slowly below T_N.This suggests that dynamic short-range AFM order of the Mn spins above the MnT_N strongly suppresses the resistivity, contrary to the conventional decreaseof \rho that is only observed upon cooling below T_N of an antiferromagnet.

Metallic behavior induced by potassium doping of the trigonal antiferromagnetic insulator EuMn2As2