Enhancement of the Curie temperature in single crystalline ferromagnetic LaCrGe${}_3$ by electron irradiation-induced disorder

Abstract

LaCrGe${}_3$ has attracted attention as a potential candidate for studies of quantum phase transitions in a ferromagnetic material. The application of pressure avoids a quantum critical point by developing a new magnetic phase. It was suggested that the disorder may provide an alternative route to a quantum critical point. We used low-temperature 2.5 MeV electron irradiation to induce relatively small amounts of point-like disorder in single crystals of LaCrGe${}_3$. Irradiation leads to an increase of the resistivity at all temperatures with some deviation from the Matthiessen rule. Hall effect measurements show that electron irradiation does not cause any detectable change in the carrier density. Unexpectedly, the Curie temperature, $T_{\text{FM}}$, \emph{increases} with the increase of disorder from approximately 90 K in pristine samples up to nearly 100 K in the heavily irradiated sample, with a tendency towards saturation at higher doses. Although the mechanism of this effect is not entirely clear, we conclude that it cannot be caused by effective ``doping" or ``pressure" due to electron irradiation. We suggest that disorder-induced broadening of a sharp peak in the density of states, $D(E)$, situated at $E_p=E_F-0.25$ eV below the Fermi energy, $E_F$, causes an increase in $D(E_F)$, leading to an enhancement of $T_{\text{FM}}$ in this itinerant ferromagnet.

References in corpus (10)

• Ambient Pressure Structural Quantum Critical Point in the Phase Diagram of (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$
• Ferromagnetic Quantum Critical Point Avoided by the Appearance of Another Magnetic Phase in LaCrGe${}_3$ under Pressure
• Formation of short-range magnetic order and avoided ferromagnetic quantum criticality in pressurized LaCrGe${}_3$
• Impact of Disorder on the Superconducting Phase Diagram in BaFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• Charge density wave and superconductivity competition in Lu${}_5$Ir${}_4$Si${}_{10}$ : a proton irradiation study
• Possible unconventional pairing in $(\text{Ca,Sr}{)}_3(\text{Ir,Rh}{)}_4{\text{Sn}}_{13}$ superconductors revealed by controlling disorder
• Small moment antiferromagnetic ordering in single crystalline La2Ni7
• Unusual coercivity and zero field stabilization of fully saturated magnetization in single crystals of LaCrGe${}_3$
• Magnetic domain depinning as possible evidence for two ferromagnetic phases in LaCrGe${}_3$
• Ion-selective scattering studied by the variable-energy electron irradiation of Ba${}_{0.2}$K${}_{0.8}$Fe${}_2$As${}_2$ superconductor

Cited by in corpus (1)

• Signatures of two ferromagnetic states and goniopolarity in LaCrGe3 in the Hall effect