Crystal structure, electronic, and magnetic properties of the bilayered rhodium oxide Sr3Rh2O7

TL;DR

This study synthesizes and characterizes the bilayered rhodium oxide Sr3Rh2O7, revealing its metallic and paramagnetic nature, structural similarity to Sr3Ru2O7, and absence of metamagnetic transition within the studied temperature and magnetic field ranges.

Contribution

First detailed structural and magnetic characterization of Sr3Rh2O7, demonstrating its metallic and paramagnetic properties and structural similarity to Sr3Ru2O7.

Findings

Sr3Rh2O7 is metallic with enhanced paramagnetism.

No evidence of spin fluctuations or metamagnetic transition from 2 K to 390 K.

Structural parameters closely match those of Sr3Ru2O7.

Abstract

The bilayered rhodium oxide Sr3Rh2O7 was synthesized by high-pressure and high-temperature heating techniques. The single-phase polycrystalline sample of Sr3Rh2O7 was characterized by measurements of magnetic susceptibility, electrical resistivity, specific heat, and thermopower. The structural characteristics were investigated by powder neutron diffraction study. The rhodium oxide Sr3Rh2O7 [Bbcb, a = 5.4744(8) A, b = 5.4716(9) A, c = 20.875(2) A] is isostructural to the metamagnetic metal Sr3Ru2O7, with five 4d electrons per Rh, which is electronically equivalent to the hypothetic bilayered ruthenium oxide, where one electron per Ru is doped into the Ru-327 unit. The present data show the rhodium oxide Sr3Rh2O7 to be metallic with enhanced paramagnetism, similar to Sr3Ru2O7. However, neither manifest contributions from spin fluctuations nor any traces of a metamagnetic transition were found within the studied range from 2 K to 390 K below 70 kOe.