Enhancement of TC and reentrant spin-glass transition in La0.86Ca0.14Mn1-yCryO3 (y = 0, 0.1 and 0.2)

TL;DR

This study investigates how chromium substitution affects the magnetic and transport properties of La0.86Ca0.14MnO3, revealing enhanced transition temperatures and reentrant spin-glass behavior with implications for magnetic materials.

Contribution

It demonstrates the enhancement of transition temperatures and the emergence of reentrant spin-glass transition in Cr-doped La0.86Ca0.14MnO3, providing new insights into magnetic phase behavior.

Findings

Transition temperature TC increases with Cr doping.

Reentrant spin-glass transition observed at Tf in Cr-doped samples.

Negative magnetoresistance decreases with Cr substitution.

Abstract

We report on the structural, frequency dependent ac susceptibility, dc magnetization and magnetoresistance (MR) measurements on polycrystalline samples of La0.86Ca0.14Mn1-yCryO3(y = 0, 0.1 and 0.2) prepared by sol-gel technique. For y = 0, a paramagnetic to ferromagnetic transition was observed at TC = 185 K. For y = 0.1, the value of TC = 200 K, an increase of 15 K and for y = 0.2, the TC = 195 K, an increase of 10 K. The imaginary part of the ac susceptibility of all the three samples shows a secondary transition at Tf < TC. For y = 0, there is no definite law to account for the frequency dependence of Tf and is attributed to a transition arising out of a canted structure. However, in the case of y = 0.1 and 0.2, the frequency dependence indicate the presence of a reentrant spin glass transition at Tf. Though all the three samples show a semi-conducting behavior between 300 and 5 K, a negative MR was observed corresponding to TC and Tf. The value of MR decreased for the Cr substituted samples.