The recently reported morphotropic phase boundary (MPB) in a number of giant magnetostrictive materials (GMMs) has drawn considerable interest to the local symmetry/structure near MPB region of these materials. In this letter, by in-situ X-ray diffraction and AC magnetic susceptibility measurements, we show that Tb0.3Dy0.7Fe2, the typical composition of Terfenol-D GMMs, has coexistence of rhombohedral and tetragonal phases over a wide temperature range in the vicinity of MPB. High resolution transmission electron microscopy provides direct evidence for local rhombohedral symmetry of the ferromagnetic phase and reveals regular-shaped nanoscale domains below 10 nm. The nano-sized structural/magnetic domains are hierarchically inside a single micron-sized stripe-like domain with the same average magnetization direction. Such domain structures are consistent with the low magnetocrystalline anisotropy and easy magnetic/structural domain switching under magnetic field, thus generating large magnetostriction at low field.

The compressive pre-stress induced magnetostriction jump effect of an [ 110] oriented TbDyFe crystal is simulated by tracking the initial redistribution of magnetic domains and their volume fraction evolutions under external magnetic fields. Through searching for the free energy minima within both ( 110) and ( 110) planes, it is found that the axial compressive pre-stress not only switches magnetizations of the 35 ∘ domains toward the perpendicular plane, but also switches magnetizations of the 90 ∘ domains approaching the [110] direction. When increasing the stress magnitude, the volume fraction for 35 ∘ domains decreases and the one for the [110] domain increases rapidly. However, the volume fraction for the four 90 ∘ domains within the perpendicular plane first increases to a maximum under a certain stress magnitude and further decreases. The stress-induced anisotropy thereafter changes the volume fraction evolutions during the magnetization process, which explains well the magnetostriction jump effect.

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Nathaniel Hawthorne, one of the classic writers of American romanticism, wrote many classic works throughout his life, including The Scarlet Letter, the representative of romantic novels and his outstanding masterpiece. Extensive attention has paid on it since it was published. Many literary critics use different theories to explain this work, many of which explore the theme including good and evil, love and hate, and culture under the influence of Puritanism. However, previous researches have paid less attention on the space feature of The Scarlet Letter, and in the traditional narratological research, the space factor has also been ignored for a long time. In this thesis, the author will take space as the starting point based on the relevant spatial theory and spatial narrative research results, and interpret the multiple space construction in The Scarlet Letter in detail, further analyzing the narrative strategy adopted by Hawthorne in order to explore the cultural connotation of the multiple spaces constructed in his works.