What is the type of hole occupied if limiting value of r + r - is in the range of 0.225 to 0.414 ?

Step-by-step solution

The radius ratio is the ratio of the radius (r) of the atom or ion which can exactly fit in the octahedral void formed by spheres of radius R . For trigonal voids, the radius ratio is 0.155 . For tetrahedral voids, the radius ratio is 0.225 . For octahedral voids, the radius ratio is 0.414 . For cubic voids, the radius ratio is 0.732 . Thus, the limiting radius ratio for tetrahedral structure is 0.225-0.414 .