B. Graneli | Searcharxiv

arXiv2013

Effect of pressure on the Cu and Pr magnetism in Nd(1-x)Pr(x)Ba2Cu3O7 investigated by muon spin rotation

The effect of pressure on the copper and praseodymium magnetic order in the system Nd(1-x)$Pr(x)Ba2Cu3$O7 with x=0.3, 0.5, 0.7, and 1 was investigated by means of the muon spin rotation (muSR) technique. It was found that the effect of pressure on the Neel temperatures of both copper and praseodymium is positive for the whole range of Pr concentrations (0.3<x<1) studied. These findings are in contrast with a number of previous reports and clarify some of the puzzles related to the effect of pressure on superconductivity and magnetism in the praseodymium-substituted R}(1-x)$Pr(x)Ba2Cu3O7 systems, where R is a rare earth element.

cond-mat.supr-con↗

arXiv2011

muSR investigation of magnetism and magnetoelectric coupling in Cu2OSeO3

A detailed zero and transverse field (ZF&TF) muon spin rotation (muSR) investigation of magnetism and the magneto-electric coupling in Cu2OSeO3 is reported. An internal magnetic field B_int(T=0) = 85.37(25) mT was found, in agreement with a ferrimagnetic state below Tc = 57.0(1) K. The temperature dependence of the magnetic order parameter is well described by the relation B_int = B(0)(1-(T/Tc)^2)^b with an effective exponent b = 0.39(1) which is close to the critical exponent B ~ 1/3 for a three dimensional (3D) magnetic system. Just above Tc the muon relaxation rate follows the power low λ(T)\propto (T/Tc - 1)^ωwith ω= 1.06(9), which is characteristic for 3D ferromagnets. Measurements of B_int(T) with and without an applied electrostatic field E = 1.66 x 10^5 V/m suggest a possible electric field effect of magnitude ΔBv = Bv(0 V)-Bv(500 V) = - 0.4(4) mT.

cond-mat.str-el↗