Rietveld refinement of step-scanned XRD patterns of [(Pr, Nd)_1−x(La, Ce)_x]_2.14Fe₁₄B powders for (a) x = 0, (b) x = 0.1, (c) x = 0.3, (d) x = 0.4, and (e) x = 0.5 at room temperature. Experimental pattern, calculated pattern, and their differences are shown in black, red, and blue colors, respectively. Bottom ticks mark the characteristic Bragg positions of RE₂Fe₁₄B, Nd, REFe₂, and Fe phases, and serve as a guide to the eye.^[23]