Modification of the ground state in Sm-Sr manganites by oxygen isotope substitution

TL;DR

This study investigates how substituting oxygen isotopes in Sm-Sr manganites significantly alters their phase diagram, inducing metal-insulator transitions and affecting magnetic and electrical properties.

Contribution

It demonstrates that oxygen isotope substitution drastically modifies the phase diagram and induces metal-insulator transitions in Sm-Sr manganites, especially near the ferromagnetic-antiferromagnetic crossover.

Findings

Oxygen isotope substitution affects phase boundaries.

Induces metal-insulator transition at specific compositions.

Modifies magnetic and electrical properties.

Abstract

The effect of $^{16}$O $\to$ $^{18}$O isotope substitution on electrical resistivity and magnetic susceptibility of Sm$_{1-x}$Sr$_x$MnO$_3$ manganites is analyzed. It is shown that the oxygen isotope substitution drastically affects the phase diagram at the crossover region between the ferromagnetic metal state and that of antiferromagnetic insulator (0.4 $< x <$ 0.6), and induces the metal-insulator transition at for $x$ = 0.475 and 0.5. The nature of antiferromagnetic insulator phase is discussed.