(Fe_0.7Co_0.3)_100–xB_x (x = 0–15, at. %) alloy films of 100 nm thickness are prepared on VN(001) single-crystalline underlayers at 600 °C and on VN poly-crystalline underlayers at room temperature (RT). A high substrate temperature of 600 °C is used to promote epitaxial film growth on VN(001) underlayer. Influences of B content on the structural, magnetic, and magnetostrictive properties are investigated. The films formed on VN(001) underlayers involve bcc(001) epitaxial crystalline phase, whereas those formed on VN poly-crystalline underlayers consist of poly-crystalline and/or amorphous phases. Surface roughness of film formed on VN(001) underlayer at 600 °C increases with increasing the B content, whereas flat surfaces are realized for the films formed on VN poly-crystalline underlayers at RT. The surface morphology is influenced by both the substrate temperature and the B content. The films with flat surfaces show good soft magnetic properties. In contrast, rough surface causes an increase in the saturation magnetic field. In the case of films formed on VN(001) single-crystalline underlayer at 600 °C, magnetostriction value of λ₁₀₀ increases from +200 × 10^–6 to +310 × 10^–6, as the B content increases from x = 0 to 5. With further increasing the B content, λ₁₀₀ value decreases due to unsaturation of magnetization at a magnetic field of 1200 Oe which is the maximum value used for measurement. λ₁₁₁ values are nearly zero (–10 × 10^–6 – +20 × 10^–6) for all the investigated B contents. Slight addition of B atoms around 5 at. % is effective in enhancing the λ₁₀₀ value, while keeping high crystallographic quality, flat surface, and soft magnetic property. On the contrary, the films formed on VN poly-crystalline underlayers at RT show moderately large λ values of about +60 × 10^–6 for all the B contents. The present study shows that control of B content and realization of flat surface are important factors in enhancing the magnetostriction of Fe-Co-B film.

  Fullerene C₆₀ shows astronomical four infrared bands (IR) of carbon rich planetary nebulae. However, there remain many unidentified bands. Our previous paper revealed that single void-defect induced graphene molecule reproduce many astronomical bands. In this paper, we investigated a series of multiple-void induced graphene molecules. We tried spin dependent DFT calculation. Model molecules are C₂₃ (one carbon pentagon ring among hexagon network), C₂₂ (two), and C₂₁ (three). Those were all magnetic molecules with spin state of Sz =2/2, 2/2 and 4/2 respectively. Calculated IR was compared with astronomical observation. The largest astronomical band at 18.9 micrometer was found in C₂₃. Second largest band at 17.4 micrometer appeared both in C₂₂ and C₂₁. Other major bands from 6 to 10 micrometer were reproduced well by a combination of C₂₃, C₂₂ and C₂₁. Similarly, larger size graphene molecules of C₅₃, C₅₂ and C₅₁ were also magnetic and reproduced astronomical bands as well. Weighting sum IR of those molecules could successfully trace astronomical 12 bands from 6 to 20 micrometer. A series of multiple void induced graphene would be major component of astronomical carbon. Fullerene C₆₀ would be one of them.