Влияние внешних воздействий на магнетизм флуктуирующих низкоразмерных электронных и спиновых корреляций в фрустрированных манганитах La-=SUB=-1-y-=/SUB=-Sm-=SUB=-y-=/SUB=-MnO-=SUB=-3+delta-=/SUB=- (y = 0.85, 1.0)

Abstract

In this work, we studied the effect of external influences on the temperature dependences of the magnetization of frustrated manganites La1ySmyMnO3+ ( ~ 0.1, у = 0.85,1.0). The two sharp peaks M (T) of different intensities found in both samples at close temperatures Т1and Т2 just above the critical temperature Тс of the phase transition to the coherent superconducting state correspond to the Lindhard divergence χL(qnest) of the temperature dependence of the paramagnetic susceptibility of stripe-like 1D electron / spin correlations modulated with wave vectors qnest1 = 2kF1 and qnest2 = 2kF2. The appearance and evolution of the features of magnetization with increasing field are explained by the formation in ab planes with complete nesting of the electron-hole sections of the Fermi surface of spatial modulation of electronic and magnetic properties in the form of fragments of two fluctuating quasi-one-dimensional charge / spin density waves incommensurate with a crystal lattice with wave vectors q1 || a and q2 || b directions. It is assumed that the strong dependence of the magnetization of fluctuating 1D CDW / SCW correlations on external influences is caused by the close proximity of the properties of the samples to the quantum critical point.