Systematic study of short-range antiferromagnetic order and the spin-glass state in lightly dopedLa2−xSrx

Abstract

Systematic measurements of the magnetic susceptibility were performed on single crystals of lightly doped La2−xSrxCuO4 (x = 0.03, 0.04 and 0.05). For all samples the temperature dependence of the in-plane magnetic susceptibility shows typical spin-glass features with spin-glass transition temperatures Tg of 6.3 K, 5.5 K and 5.0 K for x = 0.03, 0.04 and 0.05, respectively. The canonical spin-glass order parameter extracted from the in-plane susceptibility of all the samples follows a universal scaling curve. On the other hand, the out-of-plane magnetic susceptibility deviates from Curie law below a temperature T dv , higher than Tg. Comparing with previous neutron scattering results with an instrumental energy resolution of ∆ω ∼ 0.25 meV from Wakimoto et al., the xdependence of T dv is qualitatively the same as that of T el (∆ω = 0.25 meV), the temperature below which the elastic magnetic scattering develops around (π, π). Thus, a revised magnetic phase diagram in the lightly doped region of La2−xSrxCuO4 is proposed. The Curie constants calculated from the in-plane susceptibility are independent of the Sr concentration. On the basis of the cluster spin-glass model, this fact might reflect an inhomogeneous distribution of doped holes in the CuO2 plane, such as in a stripe structure. 74.72.Dn, 74.25.Ha, 75.50.Lk

Glassy low-energy spin fluctuations and anisotropy gap in La1.88Sr0.12CuO4<

“…We therefore conclude that our La 1.88 Sr 0.12 CuO 4 crystal displays low-energy dynamics that are similar to what was found in the glassy ground state of very underdoped LSCO p = 0.04. [36][37][38] Turning to magnetic order, we observe a nominally elastic signal for T < T c , see Fig. 2.…”

Separation of magnetic and superconducting behavior inYBa2Cu3O6.33(Tc=Yamani1, Buyers2, Wang3 et al. 2015Phys. Rev. B5150View full textAdd to dashboardCite

“…8(b) shows the relaxation rate decreases almost linearly on cooling down to about ∼80-100 K (dashed line) and eventually saturates to a constant value below ∼30 K. A linear temperature dependence for the relaxation rate is common in geometrically frustrated systems 51 and it is also observed for lightly doped La 2 Cu 0. 94 33 we find instead that a quadratic temperature dependence describes the relaxation rate, Γ(T)=a + bT 2 , over the entire temperature range as shown with the dash-dotted line in Fig. 8(b).…”

“…The single-layer La 2−x Sr x CuO 4 (LSCO) cuprate family has been extensively studied by neutron scattering [26][27][28][29][30][31][32][33][34][35][36] . The doped LSCO system intrinsically suffers from disorder very close to the CuO 2 planes in which both SC and AF occur.…”

Magnetic states of lightly hole-doped cuprates in the clean limit as seen via zero-field muon spin spectroscopy

“…The glassy nature of the CSG state 26 is however controversial, since magnetic structure coexists with disorder 10,27 and the observed features 28,29 are not exclusive of a true spin glass state. We simply acknowledge that increasing hole density, hence frustration, leads to a more disordered state, whose experimental signature is the abrupt flattening of the magnetic transition dependence on hole density, i.e.…”