Pole tip recession in linear tape heads: measurement technique and influence of head materials, tape speed and tape tension

Pole tip recession (PTR) in linear tape heads causes an increase in spacing and consequently an increase in signal loss. In this study, PTR in linear tape drives is analysed. Functional drive tests are conducted using thin-fi lm Al2O3-TiC and Ni-Zn ferrite heads sliding against metal particle tape. A tomic force microscopy is used to measure PTR and the recession of the over coat material used in the construction of the head. In measuring PTR, care must be taken in correctly orienting the stand-alone atomic force microscop e tip with respect to the head sample. Care must also be taken in post-proc essing the raw stand-alone atomic force microscopy data. Based on PTR data with Al2O3-TiC and Ni-Zn ferrite heads, no significant differences exist in the PTR of Al2O3-TiC heads compared with Ni-Zn ferrite heads. In the case of the Ni-Zn ferrite head, the softer Ni-Zn ferrite substrate has mechanica l properties close to those of the poles, suggesting that PTR growth should be low. However, additional third-body wear particles from the ferrite sub strate result in additional pole tip wear. No significant difference is see n in the wear of Co-Zr-Ta poles and Ni-Fe poles, as they have comparable me chanical properties. No strong conclusion may be drawn about the effect of tape speed on PTR. An increase in tape tension leads to an increase in PTR. This is a result of an increase in the normal force, which causes an incre ase in the abrasive wear. An increase in interface: contamination also lead s to an increase in PTR.