Magnetic Behaviour of the $Bi_{2-y} Sr_y Ir_2 O_7$ Pyrochlore Solid Solution

TL;DR

This study investigates the magnetic properties of Bi$_{2-y}$Sr$_{y}$Ir$_{2}$O$_{7}$ solid solutions, revealing no magnetic transitions but signs of short-range magnetic order and strong electron correlations influenced by Sr content.

Contribution

It provides new insights into the magnetic behavior and electron correlations in the Bi$_{2-y}$Sr$_{y}$Ir$_{2}$O$_{7}$ system, highlighting the effects of Sr substitution.

Findings

No magnetic transition observed from 2 to 300 K.

Magnetic susceptibility deviates from Curie-Weiss law, indicating short-range order.

Pauli susceptibility decreases with Sr content, suggesting a shift towards Ir$^{5+}$.

Abstract

The temperature dependence of magnetic susceptibility of the Bi$_{2-y}$Sr$_{y}$Ir$_{2}$O$_{7}$ system was studied from 2 to 300 K. According to these measurements, the solid solution $(0\leq y\leq 0.9)$ does not show any magnetic transition; however, a noticeable deviation from the Curie-Weiss law occurs and the magnetic behavior of this system can be ascribed to short-range magnetic order that is also present in several geometrically frustrated systems. The Pauli magnetic susceptibility decreases as the Sr content increases, this can be associated with a shift towards Ir$^{5+}$ in samples; also the Ir effective magnetic moment decreases. The estimated Wilson-ratio indicates the presence of strong electron-electron correlations.