Spin-Glass Behavior in Spinel Compound ZnCoTiO4

Antiferromagnetic short-range order and cluster spin-glass state in diluted spinel ZnTiCoO4

“…The second shoulder centered around 534.2 eV is due to the presence of surface oxygen. This analysis establishes the electronic configuration of ZnTiCoO 4 as (Zn 2+ ) A [Ti 4+ Co 2+ ] B O 4 which is in-line with the recent observations [16,17].…”

“…χ(FC) becomes temperature independent because the sample cooled in magnetic field effectively pins down the uncompensated spins in magnetic clusters, leading to temperature independent χ(FC). In the recently reported studies in ZTCO by Li et al [17] and Ruiz-León et al [16], similar bifurcation was reported. In spin-glass systems, the bifurcation between χ(ZFC) and χ(FC) curves is generally attributed to the simultaneous occurrence of two phenomena: blocking of the relaxation of the domain magnetization and the spin-freezing associated with frustrated interactions below T SG [30].…”

“…This peak is recognized as the binding energy peak of Ti-2p 1/2 electronic state. The peak binding energy separation ΔE Ti ∼ 5.9 eV between Ti-2p 3/2 and Ti-2p 1/2 electronic states indicates the presence of tetravalent Ti ions in ZTCO [17,19,25]. In addition, a weak intensity satellite peak is also noticed across ∼459.7 eV in figure 2(c).…”

“…Previous studies by Ruiz-León et al reported ferrimagnetic ordering below ∼13 K (with effective magnetic moment, μ eff ∼ 4.86 μ B ) and 17 K (μ eff ∼ 4.91 μ B ) in ZnTiCoO 4 and ZnSnCoO 4 , respectively [16]. However, recent studies by Li et al reported spin-glass behavior in ZnTiCoO 4 below 14.4 K [17]. These conflicting reports on the nature of magnetic ordering in ZTCO motivated us to investigate the magnetic properties of this compound in more detail.…”

“…The tetrahedrally coordinated Zn ion 2p spectra exhibits two distinct characteristic peaks; the peak centered around 1021.3 eV is labelled as Zn-2p 3/2 and the second cusp is centered at 1044.4 eV which is associated to the Zn-2p 1/2 electronic state. The resultant spin-orbit energy gap of ΔE Zn ∼ 23.1 eV is characteristic of the divalent oxidation state of Zn ions [17,19,20]. The core level XPS spectra of Co-2p can be deconvoluted into six different peaks forming two doublets (figure 2(b)).…”