Magnetic-field modulation experiments on colossal magnetoresistance samples: first results.

Recently we have observed a small change in the width, sigma, of the Mn-O pair distribution function when a IT magnetic field is applied. To improve our sensitivity to magnetic-field-induced changes, we have developed a magnetic field modulation technique. At each X-ray energy we collect two data points, one with field on and the other with field off: as a result we collect two scans simultaneously. The difference in these two traces provides a measure of the magnetic-field-induced change. The results for the modulation measurements will be compared to the earlier work using static magnetic fields.