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Shielded spin-valve tape heads with permanent magnet stabilization are described. Final MR of 3.5% is shown on heads with trackwidths of 5 and 9 [[micro]meter], and sensor heights of 0.5, 1.0 and 1.5 [[micro]meter]. Heads are characterized on 1/2[inch] DLT-IV tape up to 180 kfci. For isolated transitions the heads show a [PW.sub.50] of 0.8 [[micro]meter] (pulse broadening due to partial head saturation) and a baseline shift [approximately]10% that can be positive or negative, and is related with shield remanence and transfer curve hysteresis. At 120 kfci, head output for a sense current of 3 to 4 mA is [approximately] 1 [mV.sub.pp] (up to 30% of the output at 30 kfci). At high linear densities, signal loss is 0.24 dB/kfci for a 0.35 [[micro]meter] shield-to-shield spacing ([D.sub.50] of 80[approximately]100 kfci). At low linear densities the head is partially saturated, and above 60 kfci harmonic distortion is lower than -20 dB. Index Terms - magnetic recording/reading heads, magnetoresistive materials and devices, spin valve heads, tape recording.

MnIr-biased spin valves have been prepared by ion beam deposition. The magnetoresistance (MR) signal reaches 7.7% and the exchange field is 450 Oe with a coupling field of 15 Oe and a coercivity of the free layer equal to 40e. The (111) texture induced by a very thin Ta buffer layer (thickness [is less than] 10 [Angstrom]) has a strong effect in increasing the MR signal and coupling field, while decreasing the exchange field and coercivity. The blocking temperature of the MnIr-biased spin valves is 250 [degrees] C and a thermal stability study shows that the exchange field is constant up to 300 [degrees] C, under consecutive 5-h anneals at each temperature. After these anneals, the MR signal is still equal to 5%. These films show better thermal stability than equivalent samples prepared by sputtering. Index Terms--Exchange coupling, low beam deposition, magnetoresistive materials and devices, MnIr, spin valves, thermal stability.

Spin dependent tunnel junctions showing tunnel magnetoresistance (TMR) values of 39~41% were fabricated using Ion Beam Deposition (IBD). Both the electrodes and the aluminum layer deposition were done by IBD. The aluminum oxidation was performed using the assist gun with an oxygen beam (+30 V acceleration voltage applied on the grids) using mixed [O.sub.2]/Ar plasma. The oxidation was monitored in real time with a residual gas analyzer (RGA). The junction area is defined by lithography, down to 3x2 [micro][m.sup.2]. As-deposited junctions with 15 [Angstrom] of Al showed TMR of 27~29%, independent of the junction area, with resistance-area products of 0.8-1.6 M [Ohms]x[micro][m.sup.2]. This TMR value reached 40% upon annealing at 290 [degrees] C, with resistance decreasing to 0.5-0.8 M [Ohms]x[micro][m.sup.2]. Index Terms--Ion beam deposition/oxidation, spin polarized tunnel junctions