Anomalous magnetic properties of GdCrTiO5 nanoparticles

In this report, the structural and magnetic properties of GdCrTiO 5 nanoparticles were explored, which were synthesized through the sol-gel technique and subsequently calcined (at 800 °C). X-ray diffraction (XRD) studies revealed the orthorhombic crystal structure of synthesized GdCrTiO 5 nanoparticles with space group Pbam. The transmission electron microscopy (TEM) images, with selected area electron diffraction (SAED) pattern, showed the particle size as 38.0 ± 0.4 nm and single crystalline nature of the sample. The temperature dependence of dc magnetization, M( T), was measured for GdCrTiO 5 nanoparticles, and different magnetic transitions were confirmed, including the spin reorientation ( T SR ), Néel temperature ( T N ) and compensation temperatures ( T comp1 and T comp2 ) in the material. Irreversibility appeared in field-cool-cooling (FCC), and field-cool-warming (FCW) curves at low temperatures, indicating a ferromagnetic-antiferromagnetic (FM-AFM) transition. Earlier, this FM-AFM transition and T SR , T comp was not observed in bulk GdCrTiO 5 . Both the FM nature and exchange bias (EB) effect are further established from the field-dependent magnetization measurements. Furthermore, a change in isothermal magnetic entropy (−Δ S m ) of 22 ± 3 J.kg -1 .K -1 is found below 10 K, for a 7 T difference in the field. The obtained magnetic properties in this report are discussed in terms of exchange frustration originating from the competing interactions of the magnetic sublattices of the Cr 3+ and Gd 3+ in the GdCrTiO 5 nanoparticles.