# Site dilution in SrRuO$_3$: Effects on structural and magnetic properties

## TL;DR

This study explores how substituting nonmagnetic Ti into SrRuO$_3$ affects its structural and magnetic properties, revealing a complex interplay between itinerant and local moment magnetism and the emergence of Griffiths phase-like behavior.

## Contribution

It provides new insights into the effects of site dilution on SrRuO$_3$, showing that Ti substitution tunes electronic correlations without altering the structure significantly.

## Key findings

- Magnetic moment and Curie temperature decrease with Ti substitution.
- The critical exponent suggests mean-field magnetic behavior.
- Griffiths phase-like behavior appears above $T_c$.

## Abstract

We have investigated the effect of site dilution with substitution of nonmagnetic element in SrRu$_{1-x}$Ti$_x$O$_3$ ($x$ $\leq$ 0.7). The nature of ferromagnetic state in SrRuO$_3$ is believed to be of itinerant type with transition temperature $T_c$ $\sim$ 162 K. Crystallographically, SrRuO$_3$ has a distorted orthorhombic structure. Substitution of Ti$^{+4}$ (3$d^0$) for Ru$^{+4}$ (4$d^4$), however, does not introduce significant structural modification due to their matching ionic radii. This substitution, on the other hand, is expected to tune the electronic correlation effect and the $d$ electron density in system. With Ti substitution, we find that magnetic moment and Curie temperature decreases but $T_c$ remains unchanged which has been attributed to opposite tuning of electron correlation effect and density of states within framework of itinerant ferromagnetism. The estimated critical exponent ($\beta$) related to magnetization implies a mean-field type of magnetic nature in SrRuO$_3$. The value of $\beta$ further increases with $x$ which is understood from the dilution effect of magnetic lattice. The system evolves to exhibit Griffiths phase like behavior above $T_c$ which is usually realized in diluted ferromagnet following local moment model of magnetism. Our detail analysis of magnetization data indicates that magnetic state in SrRuO$_3$ has contribution from both itinerant and local moment model of magnetism.