A sputtering apparatus for sputter coating an article in a reactive environment, comprising: a vacuum chamber; a cathode having a hollow body portion; and wherein the sputtering apparatus further comprises: a substantially planar yoke provided between the cathode and chamber, the yoke including at least first and second target locations (56a; 56b) provided on a first major surface thereof, and at least third and fourth target locations (56c; 56d) provided on a second major surface thereof, the at least first and second target locations (56a; 56b) being arranged such that at least initially they face the vacuum chamber, the at least third and fourth target (56c; 56d) locations being arranged such that at least initially they face the cathode, wherein the yoke is rotatable such that, upon a rotation, the at least third and fourth target locations (56c; 56d) face the vacuum chamber and the at least first and second target locations (56a; 56b) face the cathode and, upon a further rotation, the at least first and second target locations (56a; 56b) face the vacuum chamber, and the at least third and fourth target locations (56c; 56d) face the cathode; an ion beam source, and a plurality of sputtering targets (62a-d) having sputtering material located thereon, wherein the ion beam source is arranged to be located in at least one said target location (56a- d), and wherein each said sputtering target (62a-d) is arranged to be located in any other target location (56a-d). a vacuum chamber; a cathode having a hollow body portion; and wherein the sputtering apparatus further comprises: a substantially planar yoke provided between the cathode and chamber, the yoke including at least first and second target locations (56a; 56b) provided on a first major surface thereof, and at least third and fourth target locations (56c; 56d) provided on a second major surface thereof, the at least first and second target locations (56a; 56b) being arranged such that at least initially they face the vacuum chamber, the at least third and fourth target (56c; 56d) locations being arranged such that at least initially they face the cathode, wherein the yoke is rotatable such that, upon a rotation, the at least third and fourth target locations (56c; 56d) face the vacuum chamber and the at least first and second target locations (56a; 56b) face the cathode and, upon a further rotation, the at least first and second target locations (56a; 56b) face the vacuum chamber, and the at least third and fourth target locations (56c; 56d) face the cathode; an ion beam source, and a plurality of sputtering targets (62a-d) having sputtering material located thereon, wherein the ion beam source is arranged to be located in at least one said target location (56a- d), and wherein each said sputtering target (62a-d) is arranged to be located in any other target location (56a-d). a substantially planar yoke provided between the cathode and chamber, the yoke including at least first and second target locations (56a; 56b) provided on a first major surface thereof, and at least third and fourth target locations (56c; 56d) provided on a second major surface thereof, the at least first and second target locations (56a; 56b) being arranged such that at least initially they face the vacuum chamber, the at least third and fourth target (56c; 56d) locations being arranged such that at least initially they face the cathode, wherein the yoke is rotatable such that, upon a rotation, the at least third and fourth target locations (56c; 56d) face the vacuum chamber and the at least first and second target locations (56a; 56b) face the cathode and, upon a further rotation, the at least first and second target locations (56a; 56b) face the vacuum chamber, and the at least third and fourth target locations (56c; 56d) face the cathode; an ion beam source, and a plurality of sputtering targets (62a-d) having sputtering material located thereon, wherein the ion beam source is arranged to be located in at least one said target location (56a- d), and wherein each said sputtering target (62a-d) is arranged to be located in any other target location (56a-d).