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Martensitic phase transition in an aged Fe–Pd–Rh alloy was studied using transmission electron microscopy (TEM) and x-ray diffraction. Both TEM and x-ray diffraction reveal the appearance of an intermediate structure between the fcc→L10 martensitic transformation. The intermediate phase, denoted L1m, has a monoclinic structure with lattice parameters of a=3.193 Å, b=3.684 Å, c=3.141 Å, and β=92.042°, and the normal L10 martensitic phase has an ordered structure with lattice parameters of a=3.876 Å, c=3.684 Å, and c/a=0.950, as confirmed by TEM and x-ray diffraction. [ABSTRACT FROM AUTHOR]

A reactive carbenoid in complexation of alkynyltungsten derivatives with Co(sub 2)(CO)(sub 8) has been synthesized using a novel technique. The reaction results in various intramolecular cyclizations via cyclopropanation, cyclocarbonylations and insertion of the X-H bond. The potential applications of these reactions are demonstrated by transformation of cyclopropane compounds into cyclopentenones upon heating in benzene.

Firing temperature and gas pressure effect of synthesizing Sr2Si5N8:Eu2+ were investigated. The emission intensity is positively correlated with the firing temperature under 0.1 and 0.5 MPa gas pressure. The Sr2Si5N8:Eu2+ with the highest emission intensity was found at 1700°C and 1980°C under 0.1 and 0.5 MPa gas pressure, respectively. Although the maximum emission intensity of Sr2Si5N8:Eu2+ obtained under 0.5 MPa gas pressure condition is higher than that under 0.1 MPa. The Sr2Si5N8:Eu2+ synthesized under 0.5 MPa gas pressure in the temperature range from 1600°C to 1800°C have lower emission intensities than that synthesized under 0.1 MPa indicating that the melting of Sr3N2 is an important step for the formation of Sr2Si5N8:Eu2+. Moreover, the Sr2Si5N8:Eu2+ undergoes phase transition into SrSi6N8:Eu2+ completely after elongating the heating duration to 6 h at 1980°C under 0.5 MPa gas pressure. The same feature was observed under 0.1 MPa gas pressure after firing 8 h at 1750°C. Different heating durations led to different degrees of phase transition. [ABSTRACT FROM AUTHOR]

This research paper mainly presents an investigation of the microstructures and magnetic properties of bulk ferromagnetic shape memory (FSM) FePdNi (Ni = 4, 8 at.%) alloys, by transmission electron microscopy (TEM), a magnetostrictive-meter setup, and a superconducting quantum interference device (SQUID) magnetometer. The FSM alloys were homogenized through hot and cold strain forging (SF) to a ∼38 % reduction in thickness, solution-treated (ST) with annealing recrystallization at 1100 °C or 8 h, quenched in ice brine, and then aged at 500 °C for 100 h (5 HTA). The investigation of the microstructures and magnetic properties indicated that the higher Ni content (N = 8 at.%) in the FePdNi alloy SF and ST reduced the saturation magnetostriction at RT. However, with higher Ni content in the FePdNi alloy, the decomposition of L1 + L1 twin phases into stoichiometric L1 + L1 + α structures was suppressed after the alloy was ST and aged at 5 HTA, as confirmed by TEM investigation. The result was that the FSM FePdNi alloy maintained a high saturation magnetostriction and magnetization after the alloy was ST and aged at 5 HTA. This magnetic property of the FePdNi FSM alloy makes it suitable for application in high-temperature ( T < 500 °C) and high-frequency environments. However, low Ni content FSM FePdNi (N = 4 at.%) alloy SF, ST, and aged at 5 HTA underwent decomposition of the L1 + L1 twin phases into the stoichiometric L1 + L1 + α structures, as confirmed by TEM, leading to a decrease of saturation magnetostriction and magnetization. This magnetic property of the FePdNi FSM alloy is not suitable for application in high-temperature ( T < 500 °C) environments. [ABSTRACT FROM AUTHOR]

This study investigated the effects of adding a third alloying element, Ni, to create Fe70-xPd30Nix (x = 2, 4, 6, and 8 at. % Ni) ferromagnetic shape memory alloys. The Ni replaced a portion of the Fe. The magnetostriction and microstructures of Fe70-xPd30Nix high-temperature ferromagnetic shape memory alloys were studied in detail. Investigation of the magnetostriction and microstructures indicated that the greater Ni amount in the Fe70-xPd30Nix alloys caused the less saturation magnetostriction at room temperature (RT); it was also observed that it was more difficult to generate an annealed recrystallization. However, greater Ni addition into the Fe70-xPd30Nix (x = 6 and 8 at. % Ni) alloys, the L10 + L1m twin phase decomposition into stoichiometric L10 + L1m + αbct structures could be suppressed when the alloys were aged at 500 °C for 100 h. The result was that the Fe70-xPd30Nix (x = 6 and 8 at. % Ni) alloys maintained a high magnetostriction and magnetostrictive susceptibility (Δλ|s/ΔH) after the 500 °C/100 h aged treatment. This magnetic property of the Fe70-xPd30Nix (x = 6 and 8 at. % Ni) alloys is suitable for application in a high temperature (T > 500 °C) and high frequency environment. [ABSTRACT FROM AUTHOR]