Effect of magnetism on lattice dynamics in metallic chromium

Single-crystal sample of chromium doped with ca.0.2 at.%119Sn was studied by means of a transmission M\"ossbauer spectroscopy in the temperature range of 310-315 K. An anomaly in the temperature behavior of the center shift was found at ca. 313 K, a temperature that coincides well with the N\'eel temperature of chromium. The anomaly gives evidence that the vibrations of atoms in the studied system are affected by the magnetism.Comment: 7 pages, 3 figures and 11 reference

Kinetics of transformation, border of metastable miscibility gap in Fe-Cr alloy and limit of Cr solubility in iron at 858 K

The study was aimed at determination of the position of the Fe-rich border of the metastable miscibility gap (MMG) and of the solubility limit of Cr in iron at 858 K. Towards this end a Fe73.7Cr26.3 alloy was isothermally annealed at 858 K in vacuum up to 8144 hours and M\"ossbauer spectra were recorded at room temperature after every step of the annealing. Three spectral parameters viz. the average hyperfine field, , the average isomer shift, , and the probability of the atomic configuration with no Cr atoms in the two-shell vicinity of the probe Fe atoms, P(0,0), gave evidence that the transformation process takes place in two stages. All three parameters could have been well described in terms of the Johnson-Mehl-Avrami-Kolmogorov equation, yielding kinetics parameters. The first stage, associated with the phase decomposition, proceeded much faster than the second stage, associated with the alpha-to-sigma phase transformation. The most reliable estimation of the position of the MMG and that of the value of the Cr solubility limit was obtained from the annealing time dependence of , namely 24.5 at.% Cr for the former and 20.3 at.% Cr for the latter. A comparison of these figures with the recent phase diagrams pertinent to Fe-Cr system was done.Comment: 20 pages, 16 figures, 28 references. arXiv admin note: text overlap with arXiv:1905.0515

Debye temperature of single-crystal Cr with incommensurate and commensurate magnetic structure

Single-crystals of Cr and Cr3%Mn doped with ca. 0.2 at.% 119Sn were studied by means of 119Sn-site M\"ossbauer spectroscopy. M\"ossbauer spectra recorded in the temperature range of 78-300 K were analyzed using a hyperfine field distribution method. Derived therefrom values of a center shift, CS, analyzed in terms of the Debye model yielded values of the Debye temperature, T_D = 477(56)K for Cr and T_D=282(16)K for Cr3%Mn. The difference in the T_D-value can be regarded as evidence that a spin-phonon interaction is different for the incommensurate and commensurate antiferromagnetic structure of chromium.Comment: 8 pages, 5 figures, 11 refernce

Mössbauer and heat capacity studies of ErZnSn_{2}

Heat capacity results obtained for the intermetallic compound ErZnSn_{2} were re-analysed to also consider, apart from the classical Debye model, the anharmonicity of the crystal lattice and the proper set of Einstein modes. The 119mSn Mössbauer technique was applied to derive the hyperfine interaction parameters characteristic of the two inequivalent crystallographic Sn sites in the compound studied. Quadrupole interaction constants, as measured by 119mSn Mössbauer spectroscopy, allowed for estimations of Vzz components of the electric field gradient tensor that exist at both Sn sites in the discussed compound

Analysis of heat capacity and Mössbauer data for LuZnSn_{2} compound

New analysis of heat capacity data is presented for LuZnSn_[2} compound that takes into account anharmonic effects together with the existence of Einstein modes. ^{119m} Mössbauer spectroscopy was used to monitor the hyperfine parameters at the two crystallographically inequivalent Sn sites in the studied compound. The problem of non-unique mathematical resonance spectrum description and the problem how to choose physically meaningful set of hyperfine parameters will be thoroughly discussed. Measured quadrupole interaction constants by ^{199m} Sn Mössbauer spectroscopy give estimations for V_{zz} component of electric field gradient tensor at both Sn sites in LuZnSn_{2}