The structural and magnetic properties of Tb2Fe15CF2 compound were investigated by means of X-ray diffraction and magnetization measurements. Tb2Fe15Cr2 compound has a hexagonal Th2Ni17-type structure. Negative therma...The structural and magnetic properties of Tb2Fe15CF2 compound were investigated by means of X-ray diffraction and magnetization measurements. Tb2Fe15Cr2 compound has a hexagonal Th2Ni17-type structure. Negative thermal expansion was found in Tb2Fe15Cr2 compound from 372 to 452 K by X-ray dilatometry. The coefficient of the average thermal expansion is α^- =-3.14×10^-5 K^-1. The magnetostrictive deformations from 292 to 450 K were calculated. The result showed that the spontaneous volume magnetostrictive deformation ms remains nearly constant with increasing temperature up to 360 K, but decreases with the further increase of temperature. The spontaneous linear magnetostrictive deformation λc along the c axis decreases with increasing temperature. The spontaneous linear magnetostrictive deformation, λa, in the basal-plane increases with increasing temperature up to 360 K, but decreases with further increasing temperature.展开更多
Implanting 1 ×1016 to1 ×1017 Co+/cm2 into Ni85 Fe15 alloy film anditschangesof mag netoresistantcharacters were researched . The results show that Co+ is very spectacular on modifying Ni85 Fe15 alloyfilm...Implanting 1 ×1016 to1 ×1017 Co+/cm2 into Ni85 Fe15 alloy film anditschangesof mag netoresistantcharacters were researched . The results show that Co+ is very spectacular on modifying Ni85 Fe15 alloyfilm’s magnetoresistancecharacters. Atlower dose,theanisotrop ic magnetoresistivity ratio( AMR) and thesaturated magnetic field didn’tchange almost. ATmedium dose, the saturated magnetic field does not have great change either, butits AMRisraised from 1 % upto 3% . Thisiscomparabletothebest AMRvalueof permalloy based magnetoresistant material prepared by other methods. But the ion implantation tech niqueisrathersimpler. Whentheimplanting doseishigher,its AMRisalsoenhanced notice ably. However,theincreaseof saturated field saysthe material’sstructurecharacters have changed radically.展开更多
The crystallographic and magnetic structures of Er2Fe15Al2 and Er2Fe12Al5 have been refined in Gaussian peak-shape by Rietveld analysis of Neutron diffrac- tion data. The refined results indicated that Er2Fe15Al2 comp...The crystallographic and magnetic structures of Er2Fe15Al2 and Er2Fe12Al5 have been refined in Gaussian peak-shape by Rietveld analysis of Neutron diffrac- tion data. The refined results indicated that Er2Fe15Al2 compound has Th2Ni17-type hexagonal structure （space group: P63/mmc） and Er2Fe12Al5 has Th2Zn17-type rhom- bohedral structure （space group:R 3m）. The Al atoms prefer 12j and 12k sites with occupancies 0.21 and 0.13, respectively, in Er2Fe15Al2 and prefer 18f, 18h and 6c sites with occupancies 0.35, 0.36 and 0.37, respectively, in Er2Fe12Al5. The magnetic mo- ments of all Fe atoms display ferromagnetically arrangement and the moments of Er atoms couple ferrimagnetically to the moments of the Fe atoms. The moments lie in the plane perpendicular to the six-fold axis and exhibit planar magnetic anisotropy in both samples. The values of To were given and the neutron refined results coincide with that of the magnetic measurements. The relation between magnetic properties and structures was discussed.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No. 50271022), the Excellent Young Teachers Program of MOE, China (No.1999), and the Tianjin Natural Science Foundation of China (No.043602011)
文摘The structural and magnetic properties of Tb2Fe15CF2 compound were investigated by means of X-ray diffraction and magnetization measurements. Tb2Fe15Cr2 compound has a hexagonal Th2Ni17-type structure. Negative thermal expansion was found in Tb2Fe15Cr2 compound from 372 to 452 K by X-ray dilatometry. The coefficient of the average thermal expansion is α^- =-3.14×10^-5 K^-1. The magnetostrictive deformations from 292 to 450 K were calculated. The result showed that the spontaneous volume magnetostrictive deformation ms remains nearly constant with increasing temperature up to 360 K, but decreases with the further increase of temperature. The spontaneous linear magnetostrictive deformation λc along the c axis decreases with increasing temperature. The spontaneous linear magnetostrictive deformation, λa, in the basal-plane increases with increasing temperature up to 360 K, but decreases with further increasing temperature.
文摘Implanting 1 ×1016 to1 ×1017 Co+/cm2 into Ni85 Fe15 alloy film anditschangesof mag netoresistantcharacters were researched . The results show that Co+ is very spectacular on modifying Ni85 Fe15 alloyfilm’s magnetoresistancecharacters. Atlower dose,theanisotrop ic magnetoresistivity ratio( AMR) and thesaturated magnetic field didn’tchange almost. ATmedium dose, the saturated magnetic field does not have great change either, butits AMRisraised from 1 % upto 3% . Thisiscomparabletothebest AMRvalueof permalloy based magnetoresistant material prepared by other methods. But the ion implantation tech niqueisrathersimpler. Whentheimplanting doseishigher,its AMRisalsoenhanced notice ably. However,theincreaseof saturated field saysthe material’sstructurecharacters have changed radically.
基金Nuclear Industry Science Foundation !(H7196B0109) National Nature Science Foun dation of China (19835050)
文摘The crystallographic and magnetic structures of Er2Fe15Al2 and Er2Fe12Al5 have been refined in Gaussian peak-shape by Rietveld analysis of Neutron diffrac- tion data. The refined results indicated that Er2Fe15Al2 compound has Th2Ni17-type hexagonal structure （space group: P63/mmc） and Er2Fe12Al5 has Th2Zn17-type rhom- bohedral structure （space group:R 3m）. The Al atoms prefer 12j and 12k sites with occupancies 0.21 and 0.13, respectively, in Er2Fe15Al2 and prefer 18f, 18h and 6c sites with occupancies 0.35, 0.36 and 0.37, respectively, in Er2Fe12Al5. The magnetic mo- ments of all Fe atoms display ferromagnetically arrangement and the moments of Er atoms couple ferrimagnetically to the moments of the Fe atoms. The moments lie in the plane perpendicular to the six-fold axis and exhibit planar magnetic anisotropy in both samples. The values of To were given and the neutron refined results coincide with that of the magnetic measurements. The relation between magnetic properties and structures was discussed.
