High-temperature phase transitions and low-temperature magnetic ordering inSrRuO3andCaRuO3

Abstract

Perturbed-angular-correlation (PAC) spectroscopy was used to measure nuclear-electric-quadrupole interactions in the orthorhombically-distorted perovskites SrRuO, and CaRuO, over temperatures ranging from laboratory to very high temperatures. At 77 K, PAC spectroscopy was used to measure combined electric-quadrupole and magnetic-dipole interactions in magnetically ordered SrRu03 and pure electric-quadrupole interactions in paramagnetic CaRu03. The "'In~"'Cd PAC probe was used for these measurements, and it substituted into the Ru site in SrRu03 and very likely into the Ru site in CaRu03. The temperature dependence of the electric-field-gradient (EFG) parameters for SrRu03 indicates the onset of a structural phase transition at approximately 800 K. The presence of this transition indicates that the laboratory-temperature structure of SrRu03 has lower-than-cubic symmetry. At very high temperatures) 1600 K, the structure of CaRu03, as given by the EFG parameters, becomes very similar to the laboratory-temperature structure of SrRu03. At 77 K in SrRu03, the measured Ru-site supertransferred hyperfine field is 39+3 kOe. Using "Ru and "Fe Mossbauer-effect information and other ' "In~"'Cd PAC measurements, the magnetic hyperfine fields at the Ru site in SrRu03 and at the Fe site in PrFe03 are compared. 4.2 K SR is magnetically ordered and CR is not. Thus the initial report of antiferromagnetism in CR is incorrect. Both the high-temperature crystal structures of SR and CR and the low-temperature magnetic properties, pri

perturbed angular correlation and Mössbauer effect investigations of SrRuO3 and CaRuO3

“…The estimated room temperature value of V zz is 0.79(4) × 10 21 V/m 2 , which roughly agrees with the value 0.90(5) × 10 21 V/m 2 obtained in the PAC experiment with 111 Cd probe [19], taking into account slightly different screening Sternheimer factors [20].…”

Half-metallic antiferromagnetic double perovskites:LaAVRuO6(A=CaPark1, Kwon2, Min3 2002Phys. Rev. B1164700View full textAdd to dashboardCite

“…CaRuO 3 has an orthorhombically distorted perovskite structure with GdFeO 3 -type (P bnm) [19]. SrRuO 3 also has an orthorhombic crystal structure [19].…”

“…SrRuO 3 also has an orthorhombic crystal structure [19]. For the magnetic property of CaRuO 3 , several conflicting results are reported [20][21][22].…”

Transport properties, thermodynamic properties, and electronic structure ofSrRuO3

“…The combination of good chemical stability, good metallic conductivity [3], and easy epitaxial growth on various perovskite substrates [4][5][6] makes it attractive for possible multilayer device applications [7]. There is some evidence [8] that above ≈800K the structure reverts to cubic. Nominally single crystals are therefore likely to be randomly twinned arrangements of the three orientations of orthorhombic ordering.…”