On the magnetic ground state of lead-free complex perovskite Sr(Fe1/2Nb1/2)O3

摘要: Abstract We present here the results of dc magnetization (M) measurements as a function temperature (T), field (H) and time (t) with different histories ac susceptibility frequency to understand magnetic ground state Sr(Fe1/2Nb1/2)O3 (SFN). show that zero-field cooled (ZFC) (FC) curves (M(T)) not only bifurcate but also exhibit short plateau dip in FC M(T) curve suggesting observed history dependent irreversibility may be due cluster spin-glass (CSG) freezing superparamagnetic (SPM) blocking. This is confirmed by χ(ω, T) studies which reveal critical slowing down spin dynamics per Vogel Fulcher power laws transition TSG ∼(24 ± 1) K. The attempt obtained these (τ0 ∼10−6 s) found consistent CSG picture. Further, shift Tf follows de Almeida-Thouless line T-H plane characteristic exponent m = 2/3. Further support for existence phase observation non-exponential decay thermoremanent well aging, rejuvenation memory effects below Tf. non-zero value remanent Mr without saturation shown vanish exponentially increasing T → agreement what systems. comparison states SFN CaCu3Ti4O12 (CCTO) other complex niobate perovskites terms strength nearest neighbour exchange interaction parameter J1, coordination polyhedral, disorder/dilution level sublattices, presence or absence octahedral tilts possibility alternative superexchange pathways compounds.