Vinod Singh1,Kailash Chandra1,2
Delhi Technological University1,Motilal Nehru College, University of Delhi2
Vinod Singh1,Kailash Chandra1,2
Delhi Technological University1,Motilal Nehru College, University of Delhi2
The effects of Ho substitution at A site on the structural and magnetic properties of (Gd<sub>1-y</sub>Ho<sub>y</sub>)<sub>2</sub>Ti<sub>2</sub>O<sub>7 </sub>(y = 0, 0.2, 0.4 and 0.6) single phasic pyrochlore oxides have been investigated. Magnetic Ho substitution reduces the size of crystallites as calculated from the WH graph, validating the reduction in structural ordering of the produced samples. The compounds show a tendency towards a heightened ferromagnetic interaction on Ho substitution owing to the ferromagnetic connections between the Gd and Ho cations. The fight between ferromagnetic (FM) and antiferromagnetic (AFM) interaction, which is linked to magnetic frustration and local structural disorder, is speculated to be influenced by this property. The θ<sub>CW</sub> can be regulated by doping at the A site, as demonstrated by a substantial rise in the θ<sub>CW</sub> for Gd<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> doped with Ho. This might be due to the larger spin angles of the Gd-O-Ho spin, which encourage FM interactions. Further, by partially substituting Ti with Ge (B site doping), the magnetic and structural characteristics of Ho<sub>2</sub>(Ti<sub>1-x</sub>Ge<sub>x</sub>)<sub>2</sub>O<sub>7</sub> (x = 0, 0.2, and 0.4) pyrochlore have also been investigated. Structural assessment has verified that impurity-free cubic type pyrochlore crystals form with a lattice constant that continuously lowers and follows Vegard's law. Further evidence for the pyrochlore phase's hardening of the phonon mode due to phonon anharmonic interaction came from Raman spectroscopy research. Magnetic investigations have revealed that Ho<sub>2</sub>Ti<sub>2</sub>O<sub>7</sub> elevated chemical pressure causes the ferromagnetic interaction to diminish. Furthermore, even when the temperature in both the (A and B site doping) series was reduced by up to 2K, the glassy pattern remained undetectable. It can be declared that doping at the B site controls magnetic characteristics more effectively than doping at the A site when comparing both of them. It would be stimulating to conduct further research on these system crystallographic modifications at temperatures where spin ices are known to freeze and lose their equilibrium.