It is widely assumed that heat-assisted magnetic recording (HAMR) technology can further push magnetic recording technology to and beyond 1 Tb/in2 in area density. However, one of the major concerns of HAMR technology is the robustness and long-term stability of its head-disk interface. In this paper, we report our efforts in answering the uncertainties of head-disk interface design and stability of HAMR systems. The investigations focuses on (a) heating-induced pressure change by air and evaporation and its possible effects to a slider's flying stability (b) a laser-induced slider's thermal protrusion and its effects to the slider's flying stability. Results suggest that, among the factors under consideration, the thermal protrusion effects are much more severe. Possible solutions on how to reduce such effects are also discussed.

No abstract

No abstract

Based on the systematic studies for low-lying states of the odd-$A$ $\rm {}^{49-57}Mn$ isotopes, the ground-states inversion and the rotational properties of ground-state-based sequence are revealed and discussed. The energy levels of low-lying states and electromagnetic moments in odd-$A$ $^{49-57}$Mn isotopes have been well reproduced in shell-model calculations, and the above phenomena could be understood with obviously different occupation numbers in proton orbitals such as $\pi f_{7/2}$ and $\pi p_{3/2}$, which changes similarly with the obtained quadrupole deformation in covariant density functional theory~(CDFT). After considering the coupling of collective rotation and intrinsic single-particle motion, the available experimental magnetic moments in $\rm ^{53}Mn$ and adjacent nuclei can be well explained with CDFT. The present calculations suggest that the $5/2^-$ and $7/2^-$ states in $^{53}$Mn are formed by $\pi5/2^-[312]$ and $\pi7/2^-[303]$ respectively. Together with behavior of levels, this provides proofs for the level sequences of low-lying states in $\rm ^{53}Mn$ distinct from the $K^\pi=5/2^-$ rotational band in $^{49}$Cr and other odd-$A$ Mn isotopes.

No abstract