Evidence of superspin-glass behavior in Zn0.5Ni0.5Fe2O4 nanoparticles.

We have used dc-magnetization and ac-susceptibility to investigate the superspin dynamics in 9 nm average size Zn(0.5)Ni(0.5)Fe(2)O(4) magnetic particles at temperatures (T) between 3 and 300 K.

Dynamic susceptibility evidence of surface spin freezing in ultrafine NiFe2O4 nanoparticles.

We investigated the dynamic behavior of ultrafine NiFe2O4 nanoparticles (average size D = 3.5 nm) that exhibit anomalous low temperature magnetic properties such as low saturation magnetization and high-field irreversibility in both M(H) and ZFC-FC processes. Besides the expected blocking of the superspin, observed at T1 approximately 45 K, the system undergoes a magnetic transition at T2 approximately 6 K.

High-temperature crystal structures and chemical modifications in RbH(2)PO(4).

We have used laboratory and synchrotron x-ray diffraction to investigate the structural and chemical changes undergone by polycrystalline RbH(2)PO(4) upon heating within the 30-250 °C temperature interval. Our data show no evidence of the previously reported onset of partial polymerization at T = 96 °C (Park et al 2001 J. Phys.