On the magnetism, thermal- and electrical transport of SrMoO2N

Abstract

Physical properties of perovskite-type SrMoO2N phases were studied in the temperature range of 3 K<T<300 K. The oxynitride crystallizes in a cubic unit cell (space group Pm3¯m) as revealed by neutron and x-ray diffraction measurements. The polycrystalline material shows weakly temperature dependent electrical resistivity and low glasslike heat conductivity, both reflecting the unusual strength of the scattering processes in the charge carrier transport. Based on the positive Seebeck coefficient values, holes are identified as the dominating charge carriers in SrMoO2N. Down to 150 K, the magnetic susceptibility is temperature independent and explained as enhanced Pauli paramagnetism (χ∼10−4 emu mol−1 Oe−1). The absolute value of its magnetic susceptibility is, however, half of that for SrMoO3. Simultaneously, the lower Sommerfeld coefficient γ measured for the oxynitride confirms the lower density of states near the Fermi level for SrMoO2N compared to SrMoO3. At low temperature, both SrMoO2N and SrMoO3 show Curie paramagnetism superimposed to the temperature independent Pauli paramagnetism and an anomaly at T=54 K. This anomaly is attributed to the presence of molecular oxygen in the material, while the Curie upturn is likely associated with a small amount of paramagnetic centers.

Metal oxynitrides as emerging materials with photocatalytic and electronic properties

“…106 Tantalum, niobium or tungsten perovskite oxynitrides with europium at A sites and formula EuMO 3Àx N x are ferromagnetic because of the ordering of Eu(II) S = 7/2 spins, with Curie temperatures of 5.2, 5.1 and 12 K for M = Nb, Ta and W respectively. They show low electrical conductivities and Seebeck coefficients from 15 to 30 mV K À1 .…”

Structural and magnetic properties of RTiNO2 (R=Ce, Pr, Nd) perovskite nitride oxides

“…Previous studies on nitride oxide perovskites have revealed colossal magnetoresistance [7,8], paramagnetism [9], ferrimagnetism [10], and spin glass behavior [11].…”

A study on the thermal conversion of scheelite-type ABO4 into perovskite-type AB(O,N)3

“…Interestingly, thermogravimetric analysis of the SrMoO 4 in ammonia revealed a slight mass increase of the sample at temperatures up to 600°C (Fig. 6), indicating that the oxygen, which is expected to be released from SrMoO 4 upon ammonolysis, might be stored at intermediate temperatures in the pores or interstitially in the structure as molecular oxygen 13 before being released (as shown by the mass loss of SrMoO 4 at temperatures beyond 700°C, see Fig. 6).…”